Wheat, via exorphin effects, is an appetite stimulant. Eat a whole wheat bagel or bran muffin, you want another. You also want more of other foods. You also want something to eat every two hours due to widely-swinging insulin-glucose responses: blood sugar high followed by a sharp downturn that triggers a powerful impulse to eat (thus the cravings for a snack at 9 and 11 a.m. after a 7 a.m. breakfast).
If wheat is a stimulant of appetite, then removing it should yield reduced appetite and reduced calorie intake. That is precisely what happens.
When wheat products are removed from the diet--without calorie restriction, without counting fat or carbohydrate grams, no exercise program, no cleansing regimen, no skipping meals . . . nothing--calorie intake drops 350 to 400 calories per day. This calorie figure remains curiously consistent across multiple studies in which wheat was eliminated.
400 calories per day results in 21 lbs lost over 6 months, based just on calories. (3500 calories per pound lost.) That is what happens in wheat elimination diets: 21-26 lbs lost over 6 months.
Wheat is the processed food industry's nicotine, a means of ensuring repeat food purchases. It's also low-cost (subsidized by the U.S. government), high-yield, an ingredient that even has its very own withdrawal syndrome should you miss a "hit."