When Appetite Is Suppressed, Nutrition Follows: What New GLP-1 Research Is Quietly Telling Us

A newly published paper has been sitting with me this week, and the timing feels important. The study examines micronutrient and nutritional deficiencies associated with GLP-1 receptor agonists, and while it is careful and measured in its conclusions, the implications are worth pausing over.

In simple terms, the paper outlines something clinicians would expect but the public conversation has largely skipped over: when appetite is reduced, food intake often drops in ways that are not nutritionally neutral. Over time, this can translate into insufficient energy intake, reduced protein, and emerging micronutrient deficiencies. Not because people are careless. Not because they are “doing it wrong.” But because physiology follows appetite.

What strikes me is not that this is happening, but how little space this reality is given amid the enthusiasm, marketing, and moral language surrounding weight loss right now.

In my clinical work, long before GLP-1 medications were widely available, I sat with people whose thinking had become rigid, anxious, obsessive, or flat. These were not psychological failures. They were predictable responses of a brain operating without adequate fuel. Hunger, whether intentional or unintended, changes cognition. It alters mood, flexibility, impulse control, and emotional regulation. You cannot talk someone out of those changes. You have to nourish the system they arise from.

This is the foundation of Food Mad. The book is not anti-weight-loss, nor is it anti-medication. I have seen people live easier lives after weight loss, and that reality deserves respect. What concerns me, and what this new research quietly reinforces, is how rarely we talk about brain nutrition in these conversations. Appetite suppression may reduce distress around food for some people, but the brain still has requirements. Energy, protein, iron, B vitamins, essential fats, these are not optional extras. They are prerequisites for cognitive stability.

As dietitians, our role has always been nutritional adequacy. Not perfection. Not optimisation. Adequacy. Enough nourishment for the body and brain to function safely and humanely. Many of us are increasingly uneasy watching powerful appetite-altering drugs roll out with minimal nutritional scaffolding, while social media feeds fill with ads promising control, quiet, and ease, rarely mentioning what needs to replace the missing intake.

There is also a gendered layer to this moment that is difficult to ignore. Much of the public discourse is unfolding on women’s bodies, in women’s comment sections, shaped by decades of expectation that we should be smaller, quieter, and easier to manage. The responses under posts by Oprah and Serena Williams are not shallow or vain. They are filled with grief, hope, anger, financial frustration, medical dismissal, and exhaustion. They read like women trying to make sense of ageing bodies in a system that still equates worth with manageability.

This is not about judging individual choices. Medication may be an appropriate and helpful part of care for some people. Mindfulness, movement, therapy, and rest may also matter. But nutrition cannot be treated as background noise. The brain is an organ with needs, and when those needs are not met, whether intentionally or unintentionally, there are consequences we are only beginning to measure.

The research does not say “don’t use GLP-1 medications.” What it asks, quietly and responsibly, is: what else must we attend to if we do? That question deserves nuance, compassion, and clinical honesty, not defensiveness.

My hope is that we can hold complexity without turning on one another. That we can support people seeking relief while also advocating for their brains. That we can stop framing hunger as the enemy and start asking what it is trying to protect.

This is the conversation Food Mad was written to begin. And in this moment, where appetite suppression is increasingly framed as progress, it feels more necessary than ever to keep asking what nourishes a human life, not just what reduces it.

Reference Urbina, E. M., et al. (2026). Micronutrient and Nutritional Deficiencies Associated With GLP-1 Receptor Agonists. [Journal details as published].

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