Obesity: More than just 'calories in, calories out'

Obesity has been reduced to overeating and lack of exercise for decades. The notion that weight control is all about "calories in versus calories out" is a myth that dismisses the intricate pathophysiology of obesity. The Lancet Commission on Obesity reasserted the fact that obesity is a chronic, progressive illness caused by multiple biological, environmental, and genetic factors—not a matter of a lack of willpower.

The Obesity Science: Beyond Calories In, Calories Out

1. Genetic and Epigenetic Influences

Genetics plays a significant role in obesity, with some being biologically programmed to store fat more effectively because of differences in metabolism, hunger, and energy homeostasis. Epigenetic modifications—initiated by infant diet, stress, or toxins—are additional risk factors for obesity.

2. Brain and Hormonal Dysregulation

The hypothalamus controls hunger and metabolism by hormones such as leptin, ghrelin, and insulin. In obesity, these signals become disrupted—resistance to leptin makes the brain unable to feel the stored fat, hence constant hunger. Hunger becomes, therefore, a sign of obesity, but not the etiology. We need to change our mindset away from seeing obesity as overeating but rather as a dysregulated energy balance disorder.

3. Metabolic Adaptation and Fat Storage

When people attempt to lose weight by restricting calorie intake, the body reacts by reducing metabolism and enhancing hunger, and hence long-term weight loss is not achieved. Indians, according to The Lancet Commission, have a greater percentage of body fat and visceral fat with lower BMIs, which places them at greater risk for metabolic diseases at an earlier age.

4. Gut Microbiome and Inflammation

Obesity has been associated with low-grade chronic inflammation, which interferes with insulin function and leads to diabetes and cardiovascular disease. Moreover, unbalanced intestinal microbiota influence fat storage, hunger, and metabolism, thus making weight regulation even more complicated.

Blaming Individuals Only Fuels Stigma

The "calories in, calories out" myth reinforces the false idea that obesity is about willpower and results in stigma and disqualification from health care. Far worse, internalized stigma results in self-blame, shame, and health care avoidance with associated stress, depression, and weight cycling, further leading to ill health. Obesity needs to be treated medically and through policy reform—not shame and blame.

A Call for a Science-Based Approach

Obesity needs to be acknowledged as a disease for which medical intervention, policy shift, and multi-disciplinary therapy are needed. Shaming individuals based on their weight is scientifically unsound and damaging. A better understanding of the pathophysiology of obesity is essential in informing effective therapies and public health policy.

Let's leave simple solutions behind and accept the biological complexity of obesity—only then can we change for real.

(By Dr. Aparna Govil Bhasker, Consultant Bariatric and Laparoscopic Surgeon, Saifee Hospital, Mumbai)