The Nature of Obesity 12

Abstract

The medical profession in general, believes that there are two kinds of obese persons-those who have become fat because they overeat or under-exercise; and those composing a second group whose adiposity is not closely related to diet, but is caused by an endocrine or constitutional abnormality.The first apparently scientific support of the hypothesis that obesity was often of endogenous origin, came with the finding that some obese persons had an abnormally low basal metabolic rate, on the basis of body weight. When, however, it was shown that the expenditure of energy is proportional to the surface area and not the weight, it was found that most such persons have a normal basal metabolic rate. However, it is true that there remains a small group of fatpeople whose basal rate is definitely low.Later writers maintained that a common cause of endogenous obesity was to be found in a lessened specific dynamic response to food. But the increase in metabolic rate caused by food is relatively small, so that a method possessed of a high degree of accuracy is needed in order to deal quantitatively with this phenomenon. Our prolonged study of this question has convinced us that the inherent error in the method to date, when it is applied to the human subject, is such that it precludes the possibility of making quantitative statements regarding the specific dynamic response to food in man.Other writers have attributed endogenous obesity to a constitutional anomaly of the cells which somehow lowers the rate of intracellular oxidations.

Endocrine disrupting chemicals and the developmental programming of adipogenesis and obesity

“…It was once generally believed that the root cause of obesity was a lack of will‐power (Newburgh and Johnston, 1930) that was either due to individual personality defects or perhaps a disruption of the hypothalamus that interfered with satiety (Hetherington and Ranson, 1942). In May 2009, John Birkbeck, a professor at Massey University in New Zealand, re‐energized this notion that obese individuals are wholly responsible for their condition.…”

The science of obesity: what do we really know about what makes us fat? An essay by Gary Taubes

“…As such, he blamed obesity on either a "perverted appetite" (excessive energy consumption) or a "lessened outflow of energy" (insufficient expenditure). 4 If the obese person's metabolism was normal, he argued, and they still refused to rein in their intake, that was sufficient evidence to assume that they were guilty of "various human weaknesses such as overindulgence and ignorance." 5…”

Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men: A secondary analysis of energy expenditure and physical activity

“…This is known as the “carbohydrate-insulin” hypothesis. The more conventional model sees obesity as caused by an energy balance disorder in which energy intake exceeds energy expenditure [5,6]. According to this “energy balance” hypothesis, this excessive total energy intake, regardless of the macronutrient source of the energy, is the primary cause of obesity.…”