BACKGROUND

The increasing worldwide prevalence of carbohydrate-related metabolic diseases including diabetes, obesity, metabolic syndrome, and their related long-term consequences, continues to pose a challenge to health care systems (1). Poor and unbalanced diet is considered a major environmental insult contributing to the increase in metabolic disease incidence, especially in younger individuals.

Animal models exist that mimic most features of human diabetes. Such models are useful for better understanding the connection between diet and disease, and for developing dietary guidelines and improving management of the disease (2). The male Nile rat is an effective model for the study of type-2 diabetes mellitus and metabolic syndrome due to the animal's natural genetic susceptibility to these diseases and to alteration of the progression and outcome of these diseases by diet. The pathogenesis, as well as the animal's response to nutritional manipulation, conforms to the human disease (3-6). Studies with the Nile rat have demonstrated that neutralizing the glycemic load of a standard high carbohydrate diet by adding acarbose (a drug used to treat type-2 diabetes) or enhancing insulin sensitivity by supplementing metformin (another drug for type-2 diabetes) exerted significant antidiabetic effects, demonstrating the similarities between NR and human metabolism (K. C. Hayes, unpublished results, 2014). Even as new classes of oral anti-diabetic drugs are being developed and designed (7), establishing a diet-based approach to delay or completely prevent the need for such anti-diabetic medication would be a useful adjunct for individuals suffering from type-2 diabetes mellitus or impaired glucose tolerance.

Reducing the glycemic index and/or glycemic load may reduce the risk for type-2 diabetes in humans (8-10). A recent meta-analysis of 14 studies suggests that glycemic index and glycemic load of foods are meaningful predictors of type-2 diabetes risk in younger subjects if the diet glycemic load data are updated periodically (10). This concept reportedly works as well for cardiovascular risk (11). Dietary fiber has generally proven beneficial in clinical trials focused on fruit and legume intake that improved blood glucose levels and other metabolic parameters (12-16).

Biyani et al. in U.S. Pat. No. 6,361,818 describe a low fat, high fiber carrot product containing 20-50% by weight dietary fiber in which insoluble fiber substantially exceeds soluble fiber. The product is made by combining carrot juice from crushed carrots with a variety of ingredients, concentrating the mixture, adding the concentrate to a carrot pomace, and drying the mixture under vacuum. The resulting high fiber granules are also high in sugars from the added juice. Ingestion of the granules increases satiety, decreases food consumption, and promotes weight loss.

Didden in U.S. Patent Appl. No. 2014/0127297 describes a nutraceutical composition for limiting the absorption of dietary lipids for inducing weight loss. The composition contains a high fiber carrot extract combined with insoluble fiber from apple and/or oat. The resulting compositions when orally administrated decrease absorption of dietary lipids and promote weight loss in mammals including humans.

There remains a need for nutritional compositions and methods for treating and/or preventing type-2 diabetes and its progression.

SUMMARY OF THE INVENTION

The invention provides compositions and methods for dietary modulation useful in the prevention and management of metabolic syndrome, type 2 diabetes mellitus (T2DM), and other diseases related to carbohydrate metabolism. The compositions include a dietary fiber product such as that generally known as carrot pomace (one form of which is carrot pomace powder, or CPP), which is the solid residue remaining after the commercial juicing of carrots. The methods include administering fruit or vegetable pomace, such as carrot pomace, or a food or beverage composition containing fruit or vegetable pomace to a subject, whereby the dietary fiber mixture beneficially alters carbohydrate uptake in the gastrointestinal (GI) system of the subject (and may also beneficially alter the microflora and their metabolic products released in the large intestine) and prevents, controls, or treats diseases or conditions related to carbohydrate digestion and absorption and its subsequent metabolism.

Fruit or vegetable pomace for use in the present invention is a composition that contains a mixture of soluble fiber and insoluble fiber obtained from the edible portion of fruits or vegetables, preferably in a weight ratio of soluble fiber to insoluble fiber of about 0.6 to about 1.4. While pomace such as carrot pomace is often a by-product or residue from juicing, pomace for use in the invention need not be obtained from a commercial juicing operation, but can be obtained by other methods. The insoluble fiber is selected from the group consisting of cellulose, hemicellulose, lignin, and combinations thereof, and the soluble fiber includes pectin. In preferred embodiments, the fruit or vegetable pomace is produced by a method including heat treatment, juice extraction, drying, and grinding of the residue. In preferred embodiments, the heat treatment is sufficient to raise the fruit or vegetable tissue to a temperature in the range from about 100° F. to about 200° F. In preferred embodiments, the pomace is produced by a method including the release and removal of at least 40% of the weight as juice, and the juice contains at least 3.5 wt % sugar. In certain embodiments, the pomace is produced by a method that does not include alkaline treatment, bleach treatment, extraction with hot water, or heat treatment to an extent that would denature the dietary fiber, such as heat treatment that would degrade or destroy quaternary structure of associated fiber complexes, such as soluble-insoluble fiber complexes. Excessive grinding of the pomace is also to be avoided, so as to avoid denaturation of naturally occurring soluble fiber-insoluble fiber complexes, e.g., pectin-cellulose type complexes. A pomace particle size of 60 mesh or less is preferred.

One aspect of the invention is a method of maintaining or achieving normal blood glucose concentration in response to a diabetogenic diet in a mammalian subject. The method includes periodically administering to a mammalian subject, that is consuming a diabetogenic diet, a nutritional composition comprising fruit or vegetable pomace. As a result, the subject's blood glucose concentration is maintained within a normal range or achieves a value within a normal range.

Another aspect of the invention is a method to aid in treating or preventing a disease or condition related to carbohydrate metabolism. The method includes periodically administering to a subject in need thereof a nutritional composition comprising fruit or vegetable pomace. As a result, at least one symptom of the disease or condition is reduced, or the onset or progression of the disease or condition is delayed or prevented. In embodiments of the method, the disease or condition is type 1 diabetes mellitus (also referred to herein as type 1 diabetes), type 2 diabetes mellitus (also referred to herein as type 2 diabetes), gestational diabetes mellitus, prediabetes, metabolic syndrome, or obesity.

Yet another aspect of the invention is a nutritional composition comprising fruit or vegetable pomace for use in maintaining or achieving normal blood glucose concentration in response to a diabetogenic diet in a mammalian subject.

Still another aspect of the invention is a nutritional composition comprising fruit or vegetable pomace for use in treating or preventing a disease or condition related to carbohydrate metabolism in a subject.

Even another aspect is the use of fruit or vegetable pomace to reduce weight gain, especially fat accumulation, without significantly altering normal food intake and without deterring linear growth or body weight (muscle and bone structure).

Another aspect of the invention is a nutritional composition prepared by supplementation of a food, beverage, or dietary composition with fruit or vegetable pomace. In preferred embodiments, the pomace is unbleached, pectinase-free, and sugar-reduced, i.e., containing a reduced fraction of sugars, or containing a reduced dry weight ratio of sugars to dietary fiber, compared to native plant tissue. In preferred embodiments, the pomace is in the form of small particles that do not leave a gritty mouth feel after incorporation into foods or beverages, and that form a stable aqueous suspension. When the composition is administered periodically to a mammalian subject in need thereof, the subject maintains or achieves normal blood glucose concentration. In embodiments the nutritional composition contains about 2-5 wt %, about 3-5 wt %, about 4-7 wt %, about 5-8 wt %, about 5-10 wt %, about 8-12 wt %, about 10-15 wt %, about 10-20 wt %, or at least about 3, 5, 7, 10, 12, 15, or 20 wt %, on a dry weight basis, of the pomace. In certain embodiments, the nutritional corn position is formulated as a dietary formulation containing an amount of pomace sufficient to provide at least 20% of the required daily intake of dietary fiber for the subject.

Yet another aspect of the invention is a method of maintaining or improving a health-promoting intestinal microbiome in response to a diabetogenic diet in a mammalian subject. The method includes periodically administering to the mammalian subject, who is consuming a diabetogenic diet, a nutritional composition containing a fruit or vegetable pomace, such as carrot pomace, whereby the subject's intestinal microbiome is adapted to the presence of a fiber component of said carrot pomace composition, such as by fermentation of the fiber component. In embodiments of the method, administering the carrot pomace composition alters the intestinal microbiome compared to an intestinal microbiome of the subject without administering the carrot pomace composition. In embodiments of the method, bacteria of the Prevotella genus increase as a percentage of the microbiome and the Bacteroides genus decreases. Ideally the Prevotella/Bacteroides ratio increases. Without intending to limit the invention to any particular mechanism, it is believed that the beneficial health effects of the method can result at least in part from increased fermentation of plant fiber and protein to enhance short chain fatty acid production, which in turn exert beneficial effects on gut mucosal metabolism, liver glucose and lipid metabolism, enhanced bile acid turnover and appetite control via the central nervous system. In addition, deposition of adipose tissue is decreased and body weight better regulated.

The present invention utilizes fruit or vegetable pomace as a source of dietary fiber for modulating blood glucose. “Dietary fiber” as used herein refers to the indigestible portion of food materials derived from plants. Dietary fiber is the sum of soluble fiber and insoluble fiber.

The term “fruit or vegetable pomace” as used herein refers to the solid or semi-solid residue from a juice extraction process of an edible fruit or vegetable material. Suitable fruit or vegetable materials include, but are not limited to, carrot, orange, grapefruit, apple, beet, turnip, parsnip, tomato, beans and other legumes, celery, spinach, lettuce, parsley, watercress, and mixtures thereof. Table 1 below summarizes the composition of some exemplary fruit and vegetable pomaces (all values in wt %). Carrot pomace and orange pomace are particularly preferred because of their favorably high ratio of soluble to insoluble fiber. Carrots for use in the invention include all varieties and subspecies of Daucus carrota, such as Daucus carrota sativus. The carrots can have any color, such as orange, red, yellow, purple, or white. Carrots used to prepare carrot pomace for use in the invention can be devoid of the upper leafy portion of the carrot plant (the “greens”) or can include the greens or a portion of the greens, such as a portion of the greens at the top of the carrot which is embedded in the lower portion of the carrot.

A pomace for use in the invention preferably contains from about 40 wt % to about 75 wt % total dietary fiber, preferably from about 45 wt % to about 55 wt % total dietary fiber, including from about 10 wt % to about 50 wt % soluble fiber, preferably from about 15 wt % to about 30 wt % soluble fiber, with the rest of the total dietary fiber being insoluble fiber. Preferably, the pomace has a weight ratio of soluble to insoluble fiber of from about 0.25 to about 2, more preferably from about 0.3 to about 1.5, even more preferably from about 0.6 to about 1.4. Fruit or vegetable pomace for use in the invention can be in the form of dry granules or dry powder, having particles of any desired size range, or can be provided in the form of a mash with high water content, or as an aqueous suspension.

TABLE 1Composition of Fruit and Vegetable Pomaces.Carrot PomaceCarrot PomaceApple PomaceCarrot PomacePectin-depletedOrange PomaceFruitSmart ®ComponentPowder (CPP)(1)Hydro bind ™(2)Citri-fi ®100(3)Apple Fiber(4)Total dietary55.692.068.244.1fiberSoluble Fiber22.614.033.311.9Insoluble Fiber3178.034.932.2Sugar21.47.3632.2Protein6.98.153.8Total Fat0.51.051.6Ash55.32.651.8Moisture1010.0 max7.42(1)Transimpex GmbH, Neustadter Str. 1a, 67245 Lambsheim, Germany.(2)Wm. Bolthouse Farms Europe, 43 Lake Crest Circle, Atlanta, GA 30024.(3)Fiberstar, Inc., 713 St. Croix St., River Falls, WI 54022.(4)FruitSmart, 201 Euclid Rd., Grandview, WA 98930

A fruit or vegetable pomace for use in the invention is a fiber preparation containing both soluble and insoluble fiber in a ratio that is substantially similar to that in native plant tissue. One form of fruit or vegetable pomace is carrot pomace powder (CPP), which is a by-product of a commercial carrot juicing operation. Carrot pomace for use in the invention contains dietary fiber as a major component (from about 45 wt % to about 55 wt % dietary fiber, or from about 45 wt % to about 60 wt %, or in some embodiments from about 50 to about 60 wt % dietary fiber, based on dry weight), which includes both soluble fiber and insoluble fiber. Fruit or vegetable pomace for use in the invention may include additional minor components, such as water, sugars, glycoproteins, proteins, peptides, fats, carrotenes, phytosterols, phenols, other biomolecules, minerals, and electrolytes.

A “whole fruit or vegetable powder” as used herein refers to a solid material obtained from a fruit or vegetable material, or mixture of fruit and vegetable materials, by a process including dehydration without prior removal of the juice present in the fruit or vegetable material.

As used herein, “soluble fiber” refers to the water soluble or gel-forming fiber fraction of plant material, and especially of carrot fiber, which can be broken down and typically fermented to produce short chain fatty acids by large bowel flora in the mammalian GI system. Soluble fiber includes polysaccharides such as pectin, inulin, alginate, raffinose, and vegetable bean gums (e.g., guar gum and locust bean gum). Preferred soluble fiber is pectin, which is a group of heteropolysaccharides that originate from plant cell walls and are rich in galacturonic acid. Four species are common: homogalacturonan (HGA, a linear polymer), rhamnogalacturonans I and II (RGI and RGII, highly branched polymers), and xylogalacturonan (XGA). The pectin backbone contains branched or unbranched polymer of galacturonic acid with additional sugars, including xylose, apiose, rhamnose, galactose, and arabinose, which may be included in the backbone or appended to the backbone. Many of the galacturonic acid residues in pectin are esterified, but some remain in the acidic form. The molecular weight of pectin polymers ranges from 60-130,000 g/mol.

“Insoluble fiber” as used herein refers to the water insoluble fiber fraction of plant material, and especially of carrot fiber, which is not broken down for glucose absorption by the mammalian small intestine and typically is not fermented by the large bowel flora. Insoluble fiber includes plant cell wall polysaccharides such as cellulose, hemicellulose, lignin. chitin, and xanthan. Lignin is composed of aromatic alcohol subunits, and is more hydrophobic than cellulose, hem icellulose and pectin.

Methods for determining the amounts of soluble and insoluble fiber in a plant-based food material, such as a pomace, are known. For example, American Association for Clinical Chemistry (AACC) approved gravimetric and liquid chromatography-based methods are reviewed in B. C. McLeary, et al., Cereal Foods World 56, 238-247 (2011).

As used herein, “normal blood glucose concentration” refers to the concentration of glucose in blood present in a normal individual, i.e., an individual who does not have any form of diabetes or other diseases of glucose physiology. It understood that even in a normal subject the blood glucose concentration fluctuates according to physiological condition and recent consumption of food. Tests exist which take such fluctuations into account and are capable of determining whether a subject's blood glucose concentration or its fluctuation is normal. Such tests are, for example, the oral glucose tolerance test (OGTT), random blood glucose (RBG) assessment. and fasting blood glucose (FBG) test. Any of these tests can be used to detect, for example, a normal blood glucose concentration indicating the absence of diabetes (non-diabetic profile), or an elevated blood glucose concentration that can indicate a form of diabetes. By “achieving” a normal blood glucose concentration is meant the conversion of abnormal blood glucose concentration, measured using the above-mentioned or other accepted blood glucose measurements, to normal blood glucose concentration over time as the result of a treatment according to the invention. For example, a mammal having a form of diabetes (elevated blood glucose) is treated and then attains a normal blood glucose concentration. By “maintaining” normal blood glucose concentration is meant that a mammalian subject having normal blood glucose continues to have normal blood glucose over time, especially where a subject, such as a prediabetic subject, is expected to develop abnormal blood glucose when not treated according to the invention.

A “diabetogenic diet” is a diet that is likely to lead to the development of a form of diabetes, such as type 2 diabetes, over time by continued consumption of the diet. If the same subject does not consume the diabetogenic diet, but consumes a non-diabetogenic diet rendered as such by simultaneous treatment with a fruit or vegetable pomace such as carrot pomace, then the subject will not develop diabetes over time. A diabetogenic diet can be, for example, a high carbohydrate diet, especially a diet rich in processed, rapidly released and quickly absorbed carbohydrates, which leads to the development of glucose intolerance if consumed in sufficient quantity over sufficient time.

The term “carbohydrate-rich diet” or “high carbohydrate diet” refers to a diet in which the carbohydrate calories represent at least 40% of the total energy consumed, and more typically 50% or 60% or even 70% of the total energy consumed. The percentage of the total dietary energy (kilocalories) provided by carbohydrates is calculated for a diet in which total dietary energy includes energy (calories) from carbohydrate, fat, and protein. For the purposes of defining “carbohydrate-rich” only those carbohydrates are counted that are either energy-generating monosaccharides or polysaccharides that are digested to such energy-generating monosaccharides.

The term “diet” refers to food and beverage intake averaged over a period of time, i.e., more than 7 days, i.e., 10, 15, 20, 25 or 30 days or more than one month, i.e., 2, 3, or 4 months. The terms “solid formula diet,” “liquid formula diet,” and “meal replacement” refer herein to pre-made, commercially prepared and packaged, nutritional compositions that serve as either substitutes or supplements to meals. The primary function of formula diets and meal replacements is weight loss without needing to count dietary calories. Liquid formula diets and meal replacements are typically protein-based and used in combination with a low-calorie diet in which a dieter may consume on the order of 1000 kcal per day.

The term “nutritional composition” as used herein refers to any composition of matter suitable for consumption as a food or beverage by a mammalian subject. Generally, the term refers to a prepared food or beverage composition that contains two or more natural ingredients, purified ingredients, or synthetic ingredients, and provides some measure of nutrition for the subject when consumed. A “dietary composition” is a nutritional composition that is intended to serve as a complete source of nutrition for the subject that consumes it for a period of time. A nutritional composition or dietary composition is administered “periodically” if it is administered at regular or irregular intervals over a period of time, such as daily, several times a day, or several times a week, over at least one week, preferably over 2-4 weeks, more preferably over at least 4 weeks, or at least 6 weeks, 8 weeks, 10 weeks, 12 weeks, or 4 months, 5 months, or 6 months. In a preferred embodiment, a nutritional or dietary composition of the invention is administered together with, or just before or after, a meal, such as a high carbohydrate meal. In preferred embodiments, nutritional or dietary compositions of the invention are liquid.

A “subject” according to the invention is a mammal, such as a human, house pet, or livestock animal, that receives and consumes a composition according to the invention.

A “disease or condition related to carbohydrate metabolism” as referred to herein is a disease or medical condition involving an abnormality of carbohydrate metabolism. The term “carbohydrate metabolism” refers to one or more of the biochemical pathways by which ingested carbohydrates, including digestible and non-digestible carbohydrates such as sugars, starches, celluloses and numerous other polysaccharides, are either absorbed into the bloodstream and metabolized or not absorbed into the bloodstream and passed into the large intestine where they are utilized by microbial flora or not utilized and are eliminated in the feces.

The term “prediabetic” refers herein to the status of a subject, based on the subject's blood glucose concentration, as transitioning from normal to a diabetic condition. Prediabetic subjects are a sub-group within the larger status group of “diabetic” subjects. The prediabetic status can be used to detect impending diabetes and is defined by blood glucose threshold levels measured using either FBG, RBG, or OGTT tests, or preferably measured using RBG together with OGTT, or more preferably all three tests together, in milligrams glucose per deciliter of blood (mg/dl) for humans and other mammals, including the Nile rat. For the normal Nile rat, FBG ranges from 40-60 mg/dl, while the normal RBG measured value remains below the prediabetic threshold of 75 mg/dl. Finally the OGTT value measured 30 min after glucose administration does not exceed the prediabetic value of 150 mg/dl in the Nile rat. For prediabetic humans, the FBG ranges from 100 to 124 mg/dl, while RBG remains below the diabetic threshold value of 150 mg/dl, whereas the OGTT measured value does not exceed the 175 mg/dl diabetic threshold. The coupled FBG, RBG, and OGTT measurements are diagnostic for detecting the prediabetic condition, with the OGTT measurement being more sensitive for early detection of type 2 diabetes than RGB, and both are more sensitive than FBG, which provides a strong but delayed signal.

The term “diabetic” refers herein to a disease or condition of carbohydrate metabolism characterized by the blood glucose status of a mammal. The diabetic state is defined by a blood glucose threshold level, measured in milligrams of glucose per deciliter of blood (mg/dl), that exceeds a defined threshold value for any one (or more) of the following measurements: OGTT, RBG and FBG (see Table 2). These threshold values are approximately 2-fold lower for Nile rats than for humans (except for the OGTT). The Nile rat evolved to survive in a carbohydrate-poor desert environment, and when subjected to a carbohydrate-rich diet develops T2DM much more readily and with blood glucose levels that are lower than for humans. Comparative threshold values are provided below in Table 2 for: (a) fasting blood glucose (FBG), (b) random blood glucose (RBG), and (c) oral glucose tolerance test (OGTT).

TABLE 2Threshold Blood Glucose Levels for Diagnosis of Type 2 DiabetesTest MethodNile Rats (mg/dl)Humans (mg/dl)FBGHealthy≤60≤125Diabetic>60>125RBGHealthy≤75≤150Diabetic>75>150OGTTHealthy≤150≤175(30 min)Diabetic>150>175

“Treating” a disease or condition related to carbohydrate metabolism means that, in response to a method or composition of the invention, some measure of improvement is obtained in the subject's disease or condition, as measurable by at least one health index related to the disease or condition, such as blood glucose concentration, incidence, attainment, or progression of type 2 diabetes, body weight gain, fatty liver, enlarged kidneys, or the like. Treatment of a disease or condition of carbohydrate metabolism can be synonymous with “controlling” the disease or condition; control, such as by dietary intervention, provides effective treatment, but only for as long as the intervention is continued. “Preventing” such a disease or condition refers to any measure of delay of onset of the disease or condition, up to and including, but not requiring, completely preventing the disease or condition from occurring. Preventing may also include averting the occurrence of one or more aspects of the disease or condition, but not necessarily averting other aspects or all aspects of the disease or condition from occurring. Preventing may also refer to avoiding the worsening or development of a disease or condition.

The invention can be further summarized by the following list of embodiments.1. A method of maintaining or achieving normal blood glucose concentration in response to a diabetogenic diet in a mammalian subject, the method comprising periodically administering to a mammalian subject consuming a diabetogenic diet a nutritional composition comprising fruit or vegetable pomace, whereby the subject's blood glucose concentration is maintained within a normal range or achieves a value within a normal range.1a The method of embodiment 1, wherein said pomace is a pomace obtained from a fruit or vegetable selected from the group consisting of carrot, orange, grapefruit, apple, beet, tomato, beans and other legumes, celery, spinach, lettuce, parsley, watercress, and mixtures thereof.1b. The method of embodiment 1a, wherein said pomace is carrot pomace. 2. The method of any of embodiments 1,1a, and 1b, wherein said pomace provides at least 20% of the recommended daily intake of dietary fiber for the subject.3. The method of any of the previous embodiments, wherein said diabetogenic diet provides at least 40% of the subject's dietary energy in the form of carbohydrate.4. The method of any of the previous embodiments, wherein the pomace comprises a mixture of soluble fiber and insoluble fiber.5. The method of embodiment 4, wherein the weight ratio of soluble to insoluble fiber in the carrot pomace is from about 0.6 to about 1.4.6. The method of any of embodiments 4-5, wherein the insoluble fiber is selected from the group consisting of cellulose, hem icellulose, lignin, and combinations thereof.7. The method of any of embodiments 4-6, wherein the soluble fiber comprises pectin.8. The method of any of the previous embodiments, wherein the pomace is carrot pomace which is produced by a method comprising heat treatment and juice extraction of carrots, and drying and comminution of the residue.9. The method of embodiment 8, wherein the carrot pomace is produced by a method comprising heat treatment sufficient to raise the carrot tissue to a temperature in the range from about 120° F. to about 200° F.10. The method of any of embodiments 8-9, wherein the carrot pomace is produced by a method comprising release of at least 40% of the carrot weight as juice, the juice containing at least 3.5 wt % sugar.11. The method of any of embodiments 8-10, wherein the carrot pomace is produced by a method that does not include alkaline treatment, bleach treatment, or fiber-denaturing heat treatment.12. The method of any of the previous embodiments, wherein said maintaining normal blood glucose is determined using a random blood glucose test.13. The method of any of embodiments 1-11, wherein said maintaining normal blood glucose is determined using an oral glucose tolerance test.14. The method of any of embodiments 1-11, wherein said maintaining normal blood glucose is determined using a fasting blood glucose test.15. The method of any of the previous embodiments, wherein normal blood glucose is more effectively maintained compared to periodic administering of an equivalent amount of cellulose or inulin dietary fiber.16. The method of any of the previous embodiments, wherein the nutritional composition is selected from the group consisting of foods, beverages, dietary supplements, nutraceuticals, and dietary formulations.17. The method of embodiment 16, wherein the nutritional composition is pet food.18. The method of embodiment 16, wherein the nutritional composition is a reduced carbohydrate food, beverage, or dietary formulation.19. The method of any of embodiments 1-16 and 18, wherein the subject is human.20. The method of embodiment 19, wherein the human has or is at risk of developing type 2 diabetes or obesity.21. The method of any of the previous embodiments, wherein the subject experiences weight loss.22. The method of any of the previous embodiments, wherein the progression or onset of diabetes in the subject is delayed or halted.23. The method of any of embodiments 1-18 and 21-22, wherein the subject is a house pet or livestock animal.24. The method of any of the previous embodiments, wherein from about 40% to about 70% of the subject's caloric intake is provided by carbohydrate.25. The method of any of the previous embodiments, wherein the nutritional composition is administered daily over a period of at least four weeks.26. A method to aid in treating or preventing a disease or condition related to carbohydrate metabolism, the method comprising periodically administering to a subject in need thereof a nutritional composition comprising fruit or vegetable pomace, whereby at least one symptom of the disease or condition is reduced or the onset or progression of the disease or condition is delayed or prevented.27. The method of embodiment 26, wherein said pomace is a pomace obtained from a fruit or vegetable selected from the group consisting of carrot, orange, grapefruit, apple, beet, tomato, beans and other legumes, celery, spinach, lettuce, parsley, watercress, and mixtures thereof.28. The method of embodiment 27, wherein said pomace is carrot pomace.29. The method of any of embodiments 26-28, wherein the disease or condition is selected from the group consisting of type 1 diabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus, prediabetes, metabolic syndrome, and obesity.30. The method of embodiment 29, wherein the disease or condition is type 2 diabetes mellitus.31. The method of any of embodiments 26-30, wherein the onset or progression is delayed or prevented.32. The method of any of embodiments 26-31, wherein the subject is prediabetic, and the onset of type 2 diabetes mellitus is delayed or prevented.33. The method of any of embodiments 26-32, wherein the subject has type 2 diabetes mellitus, and the progression of the diabetes is halted.34. The method of any of embodiments 26-33, wherein the subject is obese and experiences weight loss.35. The method of any of embodiments 26-34, wherein said pomace provides at least 20% of the recommended daily intake of dietary fiber for the subject.36. The method of any of embodiments 26-35, wherein the pomace comprises a mixture of soluble fiber and insoluble fiber.37. The method of embodiment 36, wherein the weight ratio of soluble to insoluble fiber is from about 0.6 to about 1.4.38. The method of embodiment 36 or 37, wherein the insoluble fiber is selected from the group consisting of cellulose, hemicellulose, lignin, and combinations thereof.39. The method of any of embodiments 36-38, wherein the soluble fiber comprises pectin.40. The method of any of embodiments 26-39, wherein the pomace is carrot pomace which is produced by a method comprising heat treatment, juice extraction, drying, and comminution.41. The method of embodiment 40, wherein the carrot pomace is produced by a method comprising heat treatment sufficient to raise the carrot tissue to a temperature in the range from about 120° F. to about 200° F.42. The method of any of embodiments 40-41, wherein the carrot pomace is produced by a method comprising release of at least 40% of the carrot weight as juice, the juice containing at least 3.5 wt % sugar.43. The method of any of embodiments 40-42, wherein the carrot pomace is produced by a method that does not include alkaline treatment, bleach treatment, or fiber-denaturing heat treatment.44. The method of any of embodiments 26-43, further comprising measuring blood glucose using a random blood glucose test.45. The method of any of embodiments 26-43, further comprising measuring blood glucose using an oral glucose tolerance test.46. The method of any of embodiments 26-43, further comprising measuring blood glucose using a fasting blood glucose test.47. The method of any of embodiments 26-46, wherein said disease or condition is more effectively treated or prevented compared to periodic administering of an equivalent amount of cellulose or inulin dietary fiber.48. The method of any of embodiments 26-47, wherein the nutritional composition is selected from the group consisting of foods, beverages, dietary supplements, nutraceuticals, and dietary formulations.49. The method of embodiment 48, wherein the nutritional composition is pet food.50. The method of any of embodiments 48-49, wherein the nutritional composition is a reduced carbohydrate food, beverage, or dietary formulation.51. The method of embodiment any of embodiments 26-50, wherein the subject is human.52. The method of any of embodiments 26-50, wherein the subject is a house pet or livestock animal.53. The method of any of embodiments 26-52, wherein from about 40% to about 70% of the subject's caloric intake is provided by carbohydrate.54. The method of any of embodiments 26-53, wherein the nutritional composition is administered daily over a period of at least four weeks.55. The method of any of embodiments 26-54, wherein the subject's total plasma cholesterol and/or plasma triglycerides are reduced.56. The method of any of embodiments 26-55, wherein the subject has hyperlipidemia, hypercholesterolemia, and/or elevated triglycerides.57. A nutritional composition comprising fruit or vegetable pomace for use in maintaining or achieving normal blood glucose concentration in response to a diabetogenic diet in a mammalian subject.58. The nutritional composition of embodiment 57, wherein said pomace is a pomace obtained from a fruit or vegetable selected from the group consisting of carrot, orange, grapefruit, apple, beet, tomato, beans and other legumes, celery, spinach, lettuce, parsley, watercress, and mixtures thereof.59. The nutritional composition of embodiment 58, wherein said pomace is carrot pomace.60. The nutritional composition of any of embodiments 57-59, wherein said diabetogenic diet provides at least 40% of the subject's dietary energy in the form of carbohydrate.61. The nutritional composition of any of embodiments 57-60, wherein the pomace comprises a mixture of soluble fiber and insoluble fiber.62. The nutritional composition of embodiment 61, wherein the weight ratio of soluble to insoluble fiber in the pomace is from about 0.6 to about 1.4.63. The nutritional composition of any of embodiments 61-62, wherein the insoluble fiber is selected from the group consisting of cellulose, hem icellulose, lignin, and combinations thereof.64. The nutritional composition of any of embodiments 61-63, wherein the soluble fiber comprises pectin.65. The nutritional composition of any of embodiments 57-64, wherein the pomace is carrot pomace which is produced by a method comprising heat treatment and juice extraction of carrots, and drying and comminution of the residue.66. The nutritional composition of embodiment 65, wherein the carrot pomace is produced by a method comprising heat treatment sufficient to raise the carrot tissue to a temperature in the range from about 120° F. to about 200° F.67. The nutritional composition of any of embodiments 65-66, wherein the carrot pomace is produced by a method comprising release of at least 40% of the carrot weight as juice, the juice containing at least 3.5 wt % sugar.68. The nutritional composition of any of embodiments 65-67, wherein the carrot pomace is produced by a method that does not include alkaline treatment, bleach treatment, or fiber-denaturing heat treatment.69. The nutritional composition of any of embodiments 57-68, wherein the nutritional composition is selected from the group consisting of foods, beverages, dietary supplements, nutraceuticals, and dietary formulations.70. The nutritional composition of embodiment 69, wherein the nutritional composition is pet food.71. The nutritional composition of any of embodiments 69-70, wherein the nutritional composition is a reduced carbohydrate food, beverage, or dietary formulation.72. The nutritional composition of any of embodiments 57-69 and 71, wherein the subject is human.73. The nutritional composition of embodiment 72, wherein the human has or is at risk of developing type 2 diabetes or obesity.74. The nutritional composition of any of embodiments 57-73, which is also for use in promoting weight loss in the subject.75. The nutritional composition of any of embodiments 73-74, which is also for use in delaying or halting the progression or onset of diabetes in the subject.76. The nutritional composition of any of embodiments 57-75, which is also for use in lowering plasma cholesterol and/or plasma triglycerides.77. The nutritional composition of any of embodiments 57-76, wherein the subject has or is at risk of developing hyperlipidemia, hypercholesterolemia, and/or elevated triglycerides.78. The nutritional composition of any of embodiments 57-71 and 74-75, wherein the subject is a house pet or livestock animal.79. The nutritional composition of any of embodiments 57-78, wherein from about 40% to about 70% of the subject's caloric intake is provided by carbohydrate.80. The nutritional composition of any of embodiments 57-79, wherein said use comprises administration daily over a period of at least four weeks.81. A nutritional composition comprising fruit or vegetable pomace for use in treating or preventing a disease or condition related to carbohydrate metabolism in a subject.82. The nutritional composition of embodiment 81, wherein said pomace is a pomace obtained from a fruit or vegetable selected from the group consisting of carrot, orange, grapefruit, apple, beet, tomato, beans and other legumes, celery, spinach, lettuce, parsley, watercress, and mixtures thereof.83. The nutritional composition of claim82, wherein said pomace is carrot pomace.84. The nutritional composition of any of embodiments 81-83, wherein said use results in at least one symptom of the disease or condition being reduced or the onset or progression of the disease or condition being delayed or prevented.85. The nutritional composition of any of embodiments 81-84, wherein the disease or condition is selected from the group consisting of type 1 diabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus, prediabetes, metabolic syndrome, and obesity.86. The nutritional composition of any of embodiments 81-85, wherein the subject is prediabetic, and the onset of type 2 diabetes mellitus is delayed or prevented.87. The nutritional composition of any of embodiments 81-86, wherein the subject has type 2 diabetes mellitus, and the progression of the diabetes is halted.88. The nutritional composition of any of embodiments 81-87, wherein the pomace comprises a mixture of soluble fiber and insoluble fiber.89. The nutritional composition of any of embodiments 81-88, wherein the weight ratio of soluble to insoluble fiber in the pomace is from about 0.6 to about 1.4.90. The nutritional composition of any of embodiments 88-89, wherein the insoluble fiber is selected from the group consisting of cellulose, hem icellulose, lignin, and combinations thereof.91. The nutritional composition of any of embodiments 88-90, wherein the soluble fiber comprises pectin.92. The nutritional composition of any of embodiments 81-91, wherein the pomace is carrot pomace which is produced by a method comprising heat treatment and juice extraction of carrots, and drying and comminution of the residue.93. The nutritional composition of embodiment 92, wherein the carrot pomace is produced by a method comprising heat treatment sufficient to raise the carrot tissue to a temperature in the range from about 120° F. to about 200° F.94. The nutritional composition of any of embodiments 92-93, wherein the carrot pomace is produced by a method comprising release of at least 40% of the carrot weight as juice, the juice containing at least 3.5 wt % sugar.95. The nutritional composition of any of embodiments 92-94, wherein the carrot pomace is produced by a method that does not include alkaline treatment, bleach treatment, or fiber-denaturing heat treatment.96. The nutritional composition of any of embodiments 81-95, wherein the nutritional composition is selected from the group consisting of foods, beverages, dietary supplements, nutraceuticals, and dietary formulations.97. The nutritional composition of embodiment 96, wherein the nutritional composition is pet food.98. The nutritional composition of any of embodiments 96-97, wherein the nutritional composition is a reduced carbohydrate food, beverage, or dietary formulation.99. The nutritional composition of any of embodiments 81-98, wherein the subject is human.100. The nutritional composition of any of embodiments 81-98, wherein the subject is a house pet or livestock animal.101. The nutritional composition of any of embodiments 81-98, wherein said use comprises administration daily over a period of at least four weeks.102. A nutritional composition prepared by supplementation of a food, beverage, or dietary composition with fruit or vegetable pomace, wherein the pomace is unbleached, pectinase-free, and sugar-reduced; and wherein periodic administration of the nutritional composition to a mammalian subject in need thereof maintains or achieves normal blood glucose concentration of the subject.103. The nutritional composition of embodiment 102, wherein said pomace is a pomace obtained from a fruit or vegetable selected from the group consisting of carrot, orange, grapefruit, apple, beet, tomato, beans and other legumes, celery, spinach, lettuce, parsley, watercress, and mixtures thereof.104. The nutritional composition of embodiment 103, wherein said pomace is carrot pomace.105. The nutritional composition of any of embodiments 102-104 which is formulated as a food product, beverage, nutritional supplement, nutraceutical, or dietary formulation.106. The nutritional composition of any of embodiments 102-105, wherein the pomace comprises a mixture of soluble fiber and insoluble fiber.107. The nutritional composition of embodiment 106, wherein the weight ratio of soluble to insoluble fiber is from about 0.6 to about 1.4.108. The nutritional composition of any of embodiments 106-107, wherein the insoluble fiber is selected from the group consisting of cellulose, hem icellulose, lignin, and combinations thereof.109. The nutritional composition of any of embodiments 106-108, wherein the soluble fiber comprises pectin.110. The nutritional composition of any of embodiments 102-109, wherein the pomace is carrot pomace which is produced by a method comprising heat treatment, juice extraction, drying, and comminution.111. The nutritional composition of embodiment 110, wherein the carrot pomace is produced by a method comprising heat treatment sufficient to raise the carrot tissue to a temperature in the range from about 120° F. to about 200° F.112. The nutritional composition of any of embodiment 110-111, wherein the carrot pomace is produced by a method comprising release of at least 40% of the carrot weight as juice, the juice containing at least 3.5 wt % sugar.113. The nutritional composition of any of embodiments 110-112, wherein the carrot pomace is produced by a method that does not include alkaline treatment, bleach treatment, or fiber-denaturing heat treatment.114. The nutritional composition of any of embodiments 102-113 that comprises at least 10 wt %, on a dry weight basis, of pomace. 115. The nutritional composition of any of embodiments 102-114 that comprises 2-5 wt %, on a dry weight basis, of pomace.116. The nutritional composition of any of embodiments 102-115 that is formulated as a dietary formulation, wherein the formulation comprises an amount of pomace sufficient to provide at least 20% of the required daily intake of dietary fiber for the subject.117. The method of any of embodiments 1-56, wherein a ratio of Prevotella bacteria to Bacteroides bacteria is increased in the subject's intestinal microbiome.118. The method of any of embodiments 1-56 or 117, wherein bacteria of the genus Lactobacillus are decreased as a percentage of the subject's intestinal microbiome.119. The method of any of embodiments 1-56 or any of embodiments 117-118, wherein the subject's postprandial blood glucose level, measured as the area under the curve (AUC) at two hours in an oral glucose tolerance test, is lowered.120. The method of embodiment 119, wherein the subject is human and consumes at least 10 g of carrot pomace per day, and wherein the subject's glucose AUC at two hours in an oral glucose tolerance test is reduced by at least about 25% compared to without consumption of carrot pomace.121. The nutritional composition of any of embodiments 57-116, wherein said use increases bacteria of the Erysipelotrichaceae family as a percentage of the subject's intestinal microbiome.122. The nutritional composition of any of embodiments 57-116 and 121, wherein said use increases a ratio of Prevotella bacteria to Bacteroides bacteria in the subject's intestinal microbiome.123. The nutritional composition of any of embodiments 57-116 and 121-122, wherein said use decreases bacteria of the genus Lactobacillus as a percentage of the subject's intestinal microbiome.

