Lack of long-term randomized scientific studies proving the diet works and is safe. A randomized study distributes participants in a deliberately random way into either the non-tested diet group or the special diet group. Some fad diets state there is research to support their claims, but the research is only done with a few people or does not exist.
I rarely have to snack at all. My breakfast is quite large and will always tied me over until lunch. I then try to eat my lunch very slowly (over an hour or so) throughout the day while working, etc. so that it will last to supper. The days I do a resistance workout, I’ll have a high protein smoothie after (which is usually in the afternoon) so that keeps me until supper.
Weight can affect a person's self-esteem. Excess weight is highly visible and evokes some powerful reactions, however unfairly, from other people and from the people who carry the excess weight. The amount of weight loss needed to improve your health may be much less than you wish to lose, when you consider how you evaluate your weight. Research has shown that your health can be greatly improved by a loss of 5–10 percent of your starting weight. That doesn't mean you have to stop there, but it does mean that an initial goal of losing 5–10 percent of your starting weight is both realistic and valuable.