WEIGHT LOSS ISN'T SIMPLE MATH

New research-backed theories explain why losing weight becomes harder as the body adapts to change and why weight-loss strategies need to differ

- AP

The settling point is defined as where body weight stabilises because energy intake equals energy expenditure, which is determined by the physical and metabolic costs of maintaining body mass

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For decades, people have been told that their weight problems can be solved by math: Calories in, calories out.

For decades, people have been told that their weight problems can be solved by math: Calories in, calories out. If weight were a simple math equation, more people would likely be the weight they desire. But it is much more complicated.

There are several theories as to why it is difficult to lose weight. Some focus on genetics and metabolism, while others claim environmental and social factors are more important. But which of these theories is correct, if any? Are people destined to be the weight their genetics, metabolism or environment dictates?

Understanding what's known and uncertain about these theories can help you potentially overcome your own biology to change your weight.

The concept of set point weight has been around since the 1950s. It suggests that the body has a regulatory system that defends a predetermined level of adipose tissue — commonly called fat — it maintains by changing hunger cues and energy expenditure. That predetermined fat level is governed by genetics, physiology and environmental factors.

This idea is supported by observations that, after weight loss, appetite increases and energy expenditure decreases until the weight is restored. In theory, this process prevents the body from starving, even with significant weight loss. One study found that hormones that stimulate hunger remain elevated and those that promote fullness are suppressed for at least 62 weeks after weight loss, even after regaining weight.