Q:

The "science of fullness" diets?

I noticed at my local convenience store a nutrition bar I hadn't seen before -- FullBar. I was intrigued by the concepts of the "science of fullness", which is documented on their site:
http://www.fullbar.com/science-of-fullness/

Fullbar is inspired by the principles of weight-loss surgery. When a person undergoes bariatric or lap band surgery, a device is installed to constrict the stomach. The result is that when food is ingested, it stretches out the upper part of the stomach, telling the brain that you're full.
When you use fullbar products, your stomach fills up on less food, causing you to feel satisfied with smaller amounts of food, so you consume fewer calories during meals, helping you lose weight.
fullbar works best when consumed 30 minutes before lunch and dinner or as a substitute for your daily snack. Make it part of your everyday routine, and fill up on any all-natural, fullbar product and a 16-ounce glass of water.
Before meals really notice your level of fullness. This is key. Assign your hunger a number from 1-10. Then when planning your meal, monitor how much food you're making and prepare a smaller portion than usual. Don't worry - even if it's only a fraction of what you'd normally eat, you'll still feel full.
As you’re eating, pay close attention to how your hunger lessens as you eat. Stop when you become satisfied, not when you become stuffed.

I have some questions about this.

Are they full of crap? I understand how stomach reduction surgery works, but is there other science corroborating this as a workable diet principle? 
Are there other diets that exploit this "make the stomach feel extra full on relatively low-calorie but stomach expanding foods before eating full meals" principle?
If #2 is yes, what types of inexpensive, tasty foods can be used to exploit this principle.. other than buying FullBars of course. :)

A:

If you look at the nutrition value of the bar it looks like their claims are largely BS. The product has high amounts of sugar and seems to fit into the mid-to-high GI/GL bracket so won't be providing a slow intake of energy (low GI foods are associated with this). And the feeling full factor is likely to come from the 500ml of water you're drinking with it rather than the bar.

The secret to feeling full is combining protein with carbohydrates, which also gives you the added benefit of aiding the transport of the increased Tryptophan from the protein. There's a tonne of studies to support this, to quote one:

The results of this study demonstrate that the macronutrient
  composition of a midday meal affects both food intake at dinner and
  self-reported measures of hunger, enjoyment and excitement about
  eating. These data support previous ﬁndings that the ingestion of
  higher protein foods can lead to an increase in satiety. Both a
  highprotein lunch and a balanced lunch led to lower food intake at an
  evening meal than an equicaloric high-carbohydrate lunch.

A:

Nope. I've switched to a mostly vegetarian diet over the past few years, and one thing I've noticed is how much more satisfying foods rich in dietary fiber are; although you do need to be careful not to eat too much fiber in a short period of time or your digestive system will not be happy. On the other hand, they are full of crap in the sense that their FullBar is, looking at the ingredients, just an ordinary granola bar. And I've seen healthier granola bars (Kashi are better).
I've never seen a diet that has pre-eating, but any diet high in (or, you know, containing) dietary fiber will be more satisfying in fewer calories than your standard meat plus more meat American diet (in my experience). So in a sense any good diet functions partly this way ("eat right and exercise").
I like the aforementioned Kashi granola bars, which appear similar in ingredients, but have much less sugar per bar. Also, a diet high in vegetables, fruits, whole grains, nuts, and seeds is likely to contain a whole ton of dietary fiber. Specifically, almonds seem like a great pre-meal snack. A normal serving is low in calories, high in fiber, and delicious (I prefer roasted and lightly salted almonds, but some people like raw almonds). I guess almonds aren't exactly cheap per ounce, but you're not supposed to eat handfuls of them at a time (a serving is something like 1/4 cup).

