There are a number reasons that diets fail in my case. Hunger, cravings, temptations, social pressure, bad information and excessive appetite.
The time to hunger, the period of time between food and hunger, is influenced by the rate of emptying of the stomach among other things. Carbohydrates are absorbed first at a rate of about 12 grams/ minute, proteins at 4, and fats at 2. There is also delays with protein and fats getting to a suitable section of intestine. Ease of digestion also impacts. Cooking and pulverization make a big difference. Consider 120 grams (~100 calories) of a mashed potato without fats verse a saturated animal fat pan fried potato, still solid. The first has a GI of 75 and the second perhaps 20. Also with the first I would be hungry in less that 1 hour, while the second perhaps 6 hours. Perhaps 150 calories of saturated fat. big difference. 100 cal/hr vs 43 cal/hr. Eat some saturated animal fat, some omega 3 fat at every meal. Saturated fats are not equal.
Cravings seem to be caused by high insulin and dropping blood sugar, likely keep fat from coming out of the fat cells. When I eat carbs, this happens. The only way to avoid his is to avoid carbohydrates. Omega 6 oils encourage excess insulin/insulin resistance/insulin effects, and make it much worse. Avoid.
Wheat, sugar, hype-tasty foods all stimulate appetite. Avoid. Social pressure and bad information is something that should be avoided, or instantly released as the words of an idiot, empty prattle, or other similar concept. Sorting good information and bad is an issue.
The obesity issue is not a single problem but a long list of factors, all of which must be identified, addressed and corrected for long term recovery. Some have one or another of the problems, some have multiple problems. There are too many people insisting that others are wrong, just because they do not have that specific issue.
I will not, any longer, comment on the sites beyond leaving an note saying I disagree, and my comments are on my site. Bate them.
Reasons to not eat wheat http://www.wheatbellyblog.com/2011/12/wheatlessness-and-the-new-normal/