Experts tell us there is no mystery to losing weight. We simply need to eat less and exercise more--and the food we do consume should be styled on the low-fat, high-carbohydrate diet recommended by health groups such as the American Heart Assn.
Yet this recipe is clearly not working. Perhaps that's because people are not following it. Or perhaps it's because such a diet inadvertently has encouraged the consumption of highly refined, starchy and sugary carbohydrates that research is beginning to indicate do not quell hunger.
While we eat for pleasure, taste and social reasons, hunger remains a crucial factor, because the more satisfied we feel, the less likely we are to go on eating simply because a food looks and tastes nice.
For this reason, scientists are now considering the effects foods have on "feelings of fullness." Foods with high levels of protein, such as fish, chicken, meat, lentils and eggs, plus fruits and vegetables, have been found to have the highest satiating effect.
High-fat, starchy baked goods such as croissants, cakes and biscuits, have been shown to give the lowest feeling of fullness per calorie, while carbohydrate-filled foods such as pasta and whole-grain versions of bread and cereals are more satiating than highly refined foods (though still less satiating than high-protein foods).
Canadian researchers at Laval University in Quebec, Canada, recently reinforced the importance of a food's satiety on total calorie intakes in a study published last year in the British Journal of Nutrition.
When obese subjects were asked to eat as much as they liked of a typical American Heart Assn.-style diet, they ate an average of 3,440 calories a day.
When allowed to eat as much as they liked of higher protein foods and carbohydrates such as pasta and rye bread, which have a low glycemic index and release sugar into the blood very slowly, they ate an average of 2,593 calories a day.
For a sedentary 280-pound man, for example, this difference of 847 calories a day would lead to a loss of about 2 pounds in just nine days.
Recently, Caesar Barber, a 56-year-old maintenance man from New York, launched the first lawsuit against fast-food firms, blaming them for his obesity-linked health problems.
While the courts have yet to decide on his case, there is no doubt that such companies are the purveyors of fat and thus calorie-laden, low-protein, high-glycemic index carbohydrate foods with an implicitly low satiating value.
For this reason it is perhaps not surprising that we find them so easy to over-consume. But we can't wait for the fast-food giants to reformulate their most popular recipes, serving food that is a lean source of protein, is accompanied by vegetables and served with low glycemic carbohydrate and fruit.
So if you want to start making changes, look at the satiating value of your meals and snacks. With hunger tamed, you may be pleasantly surprised how fattening fast foods will begin to lose their appeal and how you in turn may begin to slowly and gently lose weight.
Amanda Ursell, a dietitian and nutritionist, is a London-based freelance journalist. Her column appears on the first Monday of the month. She can be reached at firstname.lastname@example.org.