Final answer:
a) The body adjusts its metabolism Weight loss plateaus around 6 months into dieting because the body adjusts its metabolism to become more efficient at using energy, often decreasing the basal metabolic rate as a response to prolonged lower caloric intake. Exercise can mitigate the metabolic slowdown, but environmental and social factors also play roles in weight regulation.
Step-by-step explanation:
Weight loss tends to plateau around 6 months during dieting primarily because the body adjusts its metabolism. This physiological response, wherein the body becomes more efficient in using energy due to a reduced caloric intake, is a survival mechanism to prevent starvation. As a person diets over time, their basal metabolic rate (BMR) may decrease, leading to a reduced energy expenditure at rest. The body favors maintaining energy reserves, which manifests as a weight loss plateau. This adaptation makes dieting challenging and can be disheartening for those who are trying to lose weight.While factors like inactivity, genetics, and one's set point also influence weight change, it is this adaptation in metabolism that plays a key role during a diet-induced weight loss plateau.
Exercise can help offset this reduction in metabolic rate because it not only produces heat and work but also raises the metabolic rate even at rest. However, it's important to note that the efficiency of the body in converting internal energy to work is quite low, so energy loss through work is significantly greater than the work done, which also aids in weight loss.Moreover, despite predictions from set-point theory, empirical studies show no changes in metabolic rate amongst individuals who have lost significant amounts of weight compared to control groups, suggesting that factors beyond individual metabolism, such as social and environmental influences, also contribute to weight regulation.