Why Weight Alone Can't Tell You How Healthy You Are

Picture two people stepping onto the same bathroom scale. One eats her vegetables, exercises regularly, and has blood pressure and cholesterol readings a doctor would call textbook. The other skips meals, runs on stress and caffeine, and barely moves. The scale can only say that the first weighs more. By the usual social shorthand, she is the one who gets labelled unhealthy.

That is the opening argument of an explainer in The Indian Express, which asks how much a person's weight really says about their health and answers: less than most of us assume. Weight is one of the most measured things about the body, and criticism of someone's size is often framed as concern for their health. But a scale measures only the total weight of a body. Over time, a change in that number does hint at calorie balance. Gain weight and you are taking in more than you burn; lose it and you are burning more than you eat.

The more useful question, the piece suggests, is what weight leaves out. Cholesterol, blood sugar, blood pressure and heart rate do not show up on a scale. Neither does diet quality: whether someone gets vitamins and minerals from fruit, vegetables and whole foods, whether their fats come from olive oil, nuts and fish or from processed foods heavy in saturated and trans fats, whether they eat enough fibre to support digestion, blood sugar and cholesterol. Weight also cannot say how much body fat a person carries or where it sits. Visceral fat, which surrounds the internal organs, is linked to higher risk of heart disease, type 2 diabetes and some cancers, while subcutaneous fat just beneath the skin carries fewer risks. Exercise improves health even when it does not lead to weight loss, and sleep quality and stress shape health too. None of these registers on the scale.

The article is careful not to say weight is irrelevant. At a population level, people classed as overweight or obese by body mass index, a measure of weight relative to height, tend to have higher rates of cardiovascular disease, type 2 diabetes and certain cancers. But the link at the individual level is not clear-cut. Some people classed as overweight or obese have healthy blood pressure, cholesterol and blood sugar, a pattern often called metabolically healthy obesity. At the other end, someone at a "healthy" weight may carry high visceral fat, eat poorly or be sedentary. Terms such as "Tofi" (thin outside, fat inside) and "skinny-fat" have emerged to describe them.

The piece sets two people side by side. One eats a fibre-rich diet of vegetables, whole grains and healthy fats yet falls into the overweight category, because she eats more calories than she burns. The other eats a nutrient-poor diet but stays within calorie needs and is considered a healthy weight. The article asks which of them society would see as healthy, and which a doctor would.

Why, then, does weight get so much attention? The article's blunt answer is that it probably shouldn't. It is cheap and easy to measure, unlike blood tests, dietary assessments or body scans, which take more time, money and expertise. Such tests are sometimes done, but cost is usually a consideration. Weight is also visible, one of the few aspects of health apparent to others at a glance, which makes judgement easy. Society's ideas of what a healthy body looks like are deeply ingrained and not necessarily evidence-based.

The piece adds two points about weight loss itself. Losing weight through healthy lifestyle changes improves health, but changes such as more exercise and a better diet have been shown to benefit health even when no weight is lost. And the stigma surrounding obesity has been shown not to help weight loss and can undermine it.

The conclusion is practical: if health is the real concern, attention should move from weight toward diet quality, physical activity, sleep and stress, improvements in which can benefit people of every size.