Have you ever tried to lose a considerable amount of weight, maintained it for a while, but then all the weight lost came back? According to Dr Ashish Gautam, one can lose 10 or 15 kg, eat the same way for months, and feel healthier, but then hunger returns, the scale starts moving up, and the old weight slowly returns.
In an interaction with HT Lifestyle, Dr Gautam, principal director, robotic and laparoscopic surgery, Max Super Speciality Hospital, Patparganj, New Delhi, stressed that weight regain is often blamed on a lack of discipline. But during weight loss, a number of biological changes occur that can make regaining easier.
According to him, our bodies have a very strong biological drive to maintain weight. Knowing this reaction can help explain why weight regain occurs and why some people need medical treatment to maintain weight loss.
Why does weight regain happen?
Several adjustments happen in our bodies when our weight falls: “The energy expenditure is lower, which means the body needs fewer calories to keep itself going and to do daily activities. Hunger also increases.”
Which is why, Dr Gautam notes, if you lose weight, you may need fewer calories to maintain your new weight and feel hungrier. Similarly, daily movement can also decrease without notice, and such changes make it easier for the weight to return.
Hunger hormones shift, the body uses fewer calories
Our appetite is controlled by hormones and signals sent between the gut, fat tissue, and the brain. Dr Gautam noted that leptin is a hormone mainly produced by fat cells that signals the brain how much energy is stored in the body. So, leptin levels also decrease as body fat decreases.
How does it impact us? Dr Gautam explains, “When leptin levels are low, you are hungrier and energy expenditure drops. Ghrelin, the so-called hunger hormone, can rise when people lose weight, increasing their motivation to eat. GLP-1 and peptide YY play a role in controlling satiety and food intake.”
“Significant weight loss can cause hormonal changes that may lead to increased hunger. This makes a person hungrier more often and eat more to feel full. It is a biological response to losing weight,” he further added.
Therefore, the lighter the body, the fewer calories it needs to move and perform normal daily activities. Energy expenditure can also be lower than expected due to a change in body size. This response is known as ‘adaptive thermogenesis’.
Because muscle tissue requires energy, per Dr Gautam, losing muscle while dieting can further reduce your energy expenditure. Thus, the calorie deficit that leads to weight loss decreases as body weight decreases. Eventually, the same diet will keep the new weight, while small changes in food intake or activity can lead to weight gain.
The brain and gut role
The brain and gut also play a role in this. According to Dr Gautam, the brain controls hunger, satiety, food reward, and energy balance. Weight loss may enhance brain responses to food cues, which may, in turn, amplify hunger signals. “The body may also use energy more efficiently, and food may become more rewarding. These changes can persist even after a person loses weight,” he added.
The gut microbiome also helps to regulate weight. The trillions of microorganisms residing in the intestine participate in digestion, energy extraction, inflammation and metabolic signalling. These microbes may change their makeup and behaviour in response to changes in diet, Dr Gautam pointed out.
However, he clarified that research is underway to explore the relationship between gut bacteria, obesity, weight loss, and weight regain. Microbial patterns can influence how much energy the body derives from food and how that energy is used.
What keeps the weight from coming back
So, what is the long-term solution to this? Dr Gautam stresses that consistent eating habits, physical activity, and daily routines are the keys to long-term weight management.
He suggests, “Foods that are high in protein and fibre help you feel full. A healthy eating pattern can include vegetables, whole grains, legumes and other minimally processed foods. Exercise burns calories and saves muscle. Weight training helps preserve lean body mass during and after weight loss. Sleep directly affects appetite and food choices. Stress can also affect hunger and eating behaviour.”
These measures form the basis of weight management, together with medical treatment where necessary.
When is bariatric surgery an option?
According to Dr Gautam, for people in South East Asia, bariatric surgery may be considered for those with a BMI of 29 or higher, and those who have conditions such as ‘type 2 diabetes, obstructive sleep apnoea, osteoarthritis or fatty liver disease’. “People with a BMI of 35 or higher may also be considered for surgery without these conditions,” he added.
Bariatric surgery can lead to significant weight loss and improve health conditions linked to obesity. The decision depends on how weight affects daily life, long-term health risks, and how the person has responded to previous treatment, he insisted.
As for how bariatric surgery works, Dr Gautam explained that it changes the digestive system and affects appetite, food intake and metabolism. “Long-term follow-up includes proper nutrition, physical activity, supplements when needed and regular medical care,” he added.
Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.
