What Kolata tells us about is the research studies that have led to what many of us believe or know about weight. I have known the results of many of these studies but did not know what that knowledge was based on, so this is useful. One particularly interesting study involved healthy, normal-weight, psychologically "fit" young men. These men were placed on a calorie-reduction diet over several months. After they had lost a significant amount of weight they were put on a gradual increase diet to regain their former weight. Their behavior was studied throughout.
While these men were on this diet they became obsessed with food. They talked about cooking and bought cooking equipment. They felt deprived. When they started to regain the weight they lost they ate incredible amounts, 10,000 calories a day for some, and yet were not satisfied. They developed binge-eating habits.
In other words, they experienced what every dieter goes through, every person trying to lose weight.
Another study involved normal-weight persons, who had never had weight problems, who were put on diets to gain weight. They had a very difficult time of it. Even when they consumed extraordinary amounts of food.
Some of these studies found what I've known for many years - probably since the research was done and reported, actually - that people with weight problems have more fat cells than those who do not struggle with weight. When we lose weight our fat cells get thin and we feel starved. When normal people gain weight they do not develop additional fat cells, they just make their existing cells very fat. So when they lose again they do not feel starved.
Another finding: fat actually does have a genetic basis. Based on adoption and twin studies the conclusions were overwhelmingly clear. In spite of differences in environment people from the same genetic background tend to have the same body mass index.
I am expecting to read of later studies about exercise and its relationship to fat cells. The reason exercise is about the only way a person can hope to keep weight off.