Weight-loss drugs such as Ozempic, Wegovy and Mounjaro work primarily by reducing hunger. They mimic a hormone the body already produces called glucagon-like peptide-1 (GLP-1), which helps regulate appetite and feelings of fullness.

By slowing how quickly food leaves the stomach and acting on appetite centres in the brain, the drugs help people feel full sooner and stay fuller for longer, often without the constant hunger that makes many diets difficult to maintain.

The appetite-suppressing effect of these drugs can be substantial. Studies suggest people taking GLP-1 medications reduce their energy intake by between 16% and 40%.

But when food intake drops, the body still needs essential vitamins, minerals and protein to keep cells, muscles and organs functioning properly. If those nutrients are not packed into a smaller amount of food, deficiencies can develop.

Higher food intake generally increases the likelihood of meeting vitamin and mineral needs. Eating a varied diet across the week usually helps cover nutritional gaps, even if some meals are low in nutrients. But when portions shrink, that safety net disappears. With less food on the plate, food choices need to be more deliberate.

This is not a new problem. Traditional calorie-restricted diets have always carried a risk of nutrient deficiencies. The difference is that most of those diets failed because people struggled to stick to them. Ironically, that lack of adherence sometimes limited the long-term nutritional risks. When people returned to eating more normally, deficiencies could be corrected.

GLP-1 drugs change that pattern. Research shows many people regain weight quickly if they stop taking them, which means these medications might be used long term. That raises a new........

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