Caloric Model Inadequacy
The profound inadequacy of the caloric model is demonstrated by comparing a doughnut to a chicken breast. A French kruller doughnut is listed as containing 250 calories with a macronutrient breakdown of 18g of carbohydrate, 2g protein, and 20g fat. On the other hand, a chicken breast roasted with the skin on is the same. It has 251 calories. The macronutrient comparison for the chicken breast looks like this, 2g of carbohydrate, 37g of protein, and 10.8g of fat. In the weight loss model and the "calories are everything dogma", it would not matter which you eat, just eat less of either.
Although the calories are equal, the metabolic outcome of these two foods is profoundly different. The doughnut is more likely to create a detrimental hormonal impact, negatively impact hunger and may create brain chemistry changes that result in compensatory and detrimental eating behaviors later. This is one of the biggest oversights of the world of weight loss. Meals are not mutually exclusive. The composition of a meal impacts not only how much we eat at that meal, but also impacts how quickly we eat again, what we crave and how much we eat at later meals. Ever hear of continuous meal? A meal that lasts from 5pm, when we get home from work, until we go to bed. This insatiable need to eat, and crave salt/fat/sugar, occurs by playing the weight loss game (avoiding food or eating only small amounts all day).
Consuming the doughnut will create a significant surge in the hormone insulin while the chicken breast will elicit a more balanced hormonal response between insulin and glucagon. This is important because the proportion of insulin relative to glucagon is one determinant for the regulation of blood sugar and hunger. High glycemic index foods like a doughnut can create large spikes in blood sugar which may be followed by quick drops below normal. This can create significant changes in mood, energy, hunger, and subsequent fat burning. Which, then results in detrimental eating behaviors. Hunger hormones are also impacted differently. The chicken fills us up faster and keeps us full for longer. This is the reason why eating 4 doughnuts is not uncommon for many while eating 4 chicken breasts is almost impossible.
Anyone who has woken up and eaten eggs versus eating coffee and a muffin knows intuitively what the outcome will be. The eggs will give sustained energy, regulate hunger, and decrease cravings, while the coffee and muffin will not for most people. Higher protein levels stabilize blood sugar and blunt hunger. This translates to less overeating, decreased craving for sweets and more control over food quality at subsequent meals. Understanding this explains why even so called "healthy foods", like whole grain cereal, may not aid fat loss over the long term for many people.
The total caloric intake of a diet is impacted by the quality of the calories eaten. A low calorie healthy meal is neither low calorie or healthy if it causes you to eat more of the wrong things later. In other words, it may be better to look at a low calorie diet as an effect of a balanced metabolism not the cause of it.
Eating the right foods, for you, more often results in fat loss and automatic reduction in calories. The fact that you are now eating a lower calorie diet is simply an effect of a more hormonally balanced approach to eating. A doughnut and a chicken breast may have the same amount of calories but the metabolic consequence of each food could not be more different.