The analysis suggests that eating more trans fat is associated with a 21 per cent rise in the likelihood of developing heart disease, and a 28 per cent rise in the risk of dying of this condition, confirming a number of other reviews that have linked trans fats to heart disease. However, the source of trans fats in the diet may be important, said Russell de Souza, a co-author of the study and an assistant professor of epidemiology and biostatistics at McMaster University in Hamilton, Ontario. [3 Tips for Eating Less Trans Fat] 
 
 "Industrially produced" trans fats, which are man-made fats added to foods such as shortening and baked goods, appear to be more harmful than "ruminant" trans fats, which naturally occur in smaller amounts in foods such as butter and beef, de Souza told Live Science. “The results of this review support existing guidance to avoid industrially produced trans fats,” said Victoria Taylor, a dietician for the British Heart Foundation charity. The researchers did not find evidence that healthy adults who consume diets higher in saturated fats — the kind of fat found in meat, milk, cheese and egg yolks — face a greater chance of heart disease, according to the findings, published today (Aug. 11) in the journal The BMJ. The U.S. Dietary Guidelines also recommend limiting trans fats — such as the partially hydrogenated oils often found in cookies, crackers, baked goods and stick margarines — to less than 1 percent of daily calories, to reduce the risk of heart disease and stroke. But replacing saturated fats with refined carbohydrates, such as sugars and starches, is not the best way to reduce health risks, de Souza said.  Saturated fats are not associated with an increased risk of death, heart disease, stroke, or type 2 diabetes, finds a study published in The BMJ this week.
– If nothing else can get you to cut back on trans fats, maybe the threat of death will do it. Researchers who analyzed 123 observational studies on saturated and trans fats published in the last 30 years found people who consumed a diet high in saturated fats saw no increased risk of ischemic stroke, Type 2 diabetes, coronary heart disease, cardiovascular disease, or death from all causes—though the certainty was "very low" and researchers say they may pose other health risks, per New Scientist. People who consumed a diet high in trans fats, however, saw a 34% boost in their risk of death from any cause, a 21% increased risk of CHD, and a 28% higher risk of death from CHD, per a press release. They found no link between trans fats and ischemic stroke and couldn't confirm an association between trans fats and Type 2 diabetes based on inconsistencies in the studies reviewed. Saturated fats generally come from animal products, like butter, meat, and egg yolks, and some plant products, like chocolate and palm oils. "Ruminant" trans fats also occur naturally in some of those foods. But it's the "industrially produced" trans fats in margarine and processed food that consumers should limit, lead author Russell de Souza tells LiveScience. Made from plant oils, these fats—to be phased out within three years—are more harmful. However, "there is no one nutrient or food that's responsible for all heart disease, diabetes, or death," de Souza says. "The whole diet matters." That means when cutting back on fats, people should be careful not to replace them with other poor choices, like sugars and starches. Instead, choose fruits and vegetables, whole grains, beans, peas, nuts, and unsaturated fats like olive and canola oils, de Souza says. (You might also want to steer clear of Southern food.)