Your Body Weight Set Point
The levels of fat and your body weight are regulated by biological signals. These control your digestion, appetite, metabolism and energy balance. Together, the signals determine your body weight set point.
Your body’s set point is part of a basic biological instinct.
When body weight and fat levels fall below your set point, your body activates defense mechanisms to maintain body weight and fat in order to prevent starvation, even in people with obesity.
Everyone’s set point is different and can be changed. It appears that the body regulates fat set points similarly to how it regulates other body functions such as blood glucose, cholesterol, and blood pressure. Set points are affected by genetic, developmental, and environmental factors. Changes in any of these factors can lead us to an elevated set point for body fat storage. For example, changes in chemicals and nutrients contained in our foods can affect our brains in ways that increase the amount of food we eat and increase our body fat set point.
Additionally, as you gain weight, your set point is increased and your body works to defend the higher set point. Your body is smart, and it adapts when new things come its way. But, sometimes it’s not for the better.
Your body doesn’t realize it’s overweight and it continues to store higher amounts of fat than necessary.
Why dieting and exercise may not be enough to fight obesity
Because your body works to defend its set point, dieting and exercising are rarely effective in helping people with obesity achieve and maintain a healthy weight long-term. When you go on a diet, your body thinks it’s being starved and its survival instincts kick in causing it to store energy-rich body fat, and you can’t lose weight easily.
Unfortunately, your body’s hormones are working against you
When you lose weight, lower body fat levels trigger hormones that encourage the body to get back to its previous weight set point. A New England Journal of Medicine study showed that while dieters may initially lose weight, their bodies change levels of hormones that encourage weight regain in response to weight loss. These hormones increase appetite, decrease feelings of fullness, and slow down metabolism. The study also found that these hormones had not returned to prediet levels even 12 months after the initial weight loss, meaning their bodies were still encouraging weight regain a year after they stopped dieting.1 This is a powerful defense mechanism and may explain why the majority of weight loss attempts fail.
Bariatric surgery may reset your set point
In order for a person with obesity to achieve significant long-term weight loss, the body’s weight regulation system must be reset so that the body will stop storing excess fat. By altering the complex relationship your body has with food and its metabolism, bariatric surgery helps reset your body’s ability to effectively manage weight. New research indicates that some types of bariatric surgery, including gastric bypass and sleeve gastrectomy, have metabolic impacts that enable a new, lower body weight set point, allowing the body to return to a lower body fat level. By altering the anatomy of the stomach and/or intestine, these surgeries affect hormonal signals, resulting in decreased appetite, increased feelings of fullness, increased metabolism, and healthier food preferences. These positive changes allow your body to lose weight without the internal fight to return to the higher body weight set point.
-Adapted from Ethicon Realize
1. Sumithran et al, Long-term persistence of hormonal adaptations to weight loss, NEJM, October 2011, 1957-1604.
Am I a candidate?