Even if you eat in upscale restaurants in the U.S. or most other high-income countries, you normally are served meals with considerably more calories than you need. If you want to maintain a “Normal” BMI (Body Mass Index) you need to eat only a portion of the meal and take the rest home. It is even worse if you either (1) eat in downscale restaurants or (2) eat at fancy restaurants with 10-course “tasting menus. And if you eat enough to weigh 100 pounds or more too much you can expect to die 14 years younger than a person with normal BMI.
America is blessed with amazing amounts and varieties of foodstuffs. Unfortunately, it is also cursed with the amazing amounts and varieties of both charlatans and well-meaning-but-naïve citizens who preach wide-of-the-mark eating habits and diets. And a lot of those charlatans are large food companies with whopping ad budgets.
We have had low-fat diets, low-carbohydrate diets (e.g., the Atkins Diet), a flock of diet systems (Weight Watchers et al), the Mediterranean Diet, and lots of others. The latest is the gluten-free diet, which has nicely been debunked by Sophie Egan. Ms. Egan makes the interesting point that Americans are judging their food based on what the foods lack rather than what they contain, which probably is a consequence of people’s being more concerned about dieting to lose weight than about eating sane amounts of nutritious food to stay healthy.