When appetite becomes smaller, the quality and adequacy of meals deserve attention.

Feeling less hungry may bring enormous relief to someone who has struggled with constant thoughts about food. But the ability to eat less should come with help to eat adequately.

My concern is that we sometimes praise the reduction in appetite without asking what remains on the plate. A person who skips meals, struggles with nausea or lives on a very narrow range of foods needs more than congratulations about weight loss.

Food education should be part of the treatment conversation from the beginning. It should help people choose meals they can tolerate, afford and enjoy while meeting their nutritional needs.

Appetite reduction is real

In a randomised study of 72 adults with obesity, semaglutide 2.4 mg reduced appetite and food cravings. At week 20, energy intake at a freely eaten test lunch was 35% lower than with placebo. That was a measured response to one test meal, not proof that every patient's daily intake falls by that percentage. 

For some people, having quieter hunger signals may make meal planning easier. For others, eating enough becomes difficult. We should ask about the individual's experience instead of assuming that reduced intake always improves diet quality.

The practical question is what someone can eat consistently. How many meals are they missing? Are they drinking enough? Is food variety shrinking? Can they manage a source of protein without discomfort?

Nutrient concerns need careful interpretation

A 2025 retrospective study examined insurance claims for 461,382 adults newly prescribed GLP-1 medicines. Most had type 2 diabetes. Nutritional deficiency diagnoses were recorded in 22.4% within 12 months, with vitamin D deficiency the most common. 

That finding warrants attention, but it does not mean the medicine caused a deficiency in one in five people. Claims data depend on testing and coding, and previously undiagnosed deficiencies may be discovered during treatment. The study also had substantial links to Abbott, a nutrition-product company. Its results support screening and further research, not a universal causal risk estimate. 

Readers should be cautious about advertisements using such statistics to sell a supplement package. A potential nutritional problem deserves assessment of the person, their intake and their medical history.

Smaller meals still need variety

A 2024 review of nutrition during anti-obesity treatment recommends attention to protein, fibre, micronutrients and fluids, with dietitian involvement where available. It is a clinical review, not evidence that everyone using a medicine requires the same meal plan or supplement. 

The Australian Guide to Healthy Eating includes vegetables and legumes, fruit, mostly wholegrain foods, protein foods, and dairy or suitable alternatives. These groups offer a useful starting point for variety, adapted to medical needs and individual tolerance. 

I suggest thinking about a few manageable meal options rather than pursuing a perfect diet. Examples to discuss with a dietitian include eggs with vegetables; plain yoghurt with fruit; fish or tofu with cooked vegetables; or a lentil dish with a suitable portion of grain food. These are starting ideas, not a prescribed menu.

Some people tolerate smaller meals more comfortably than a large evening meal. Others need temporary changes because particular foods worsen symptoms. A person with suspected delayed stomach emptying needs individual advice; simply adding more raw vegetables or fibre may be inappropriate.

Protein deserves a plan

It is easy for protein foods to disappear when someone eats very little. A breakfast of coffee alone and a dinner of a few crackers might satisfy a diminished appetite while providing little structure to the day's nutrition.

My practical suggestion is to identify tolerable protein foods for several eating occasions. Eggs, fish, poultry, yoghurt, tofu and legumes provide different options. A dietitian can help translate a daily requirement into ordinary portions rather than leaving the person to guess.

Avoid copying a high-protein target from social media. Age, body size, kidney function and other conditions affect what is suitable. A 2025 joint advisory also emphasises that adequate protein should be accompanied by resistance exercise when protecting muscle is a goal. 

Protein supplements can sometimes help bridge a shortfall. They should solve an identified problem, with food remaining part of the plan wherever possible. A blanket rule that nobody needs a supplement would be as unhelpful as insisting everybody buy one.

Hydration and digestive symptoms belong in the review

Persistent nausea, vomiting or difficulty eating should be discussed with the prescriber. The nutrition review identifies gastrointestinal symptoms and fluid intake as relevant parts of care. 

A practical approach is to note when symptoms occur, what you can keep down and whether your intake changes after a dose increase. Bring that information to the clinician. If you have a fluid restriction, follow your prescribed advice rather than a generic online water target.

Do not interpret ongoing inability to eat as evidence that treatment is working especially well. Seek prompt medical advice if you cannot keep fluids down, become faint or develop severe abdominal pain.

What food education should actually teach

I would like every person starting treatment to leave with answers to four practical questions:

1. What meals can I prepare when I have little appetite?

2. How will we assess whether I am eating enough for my needs?

3. Which symptoms mean I should contact the clinician?

4. Who can help me adapt the plan if my budget, digestion or food preferences change?

The answers should fit the household. An elaborate plan is of limited use to someone working shifts or caring for an unwell partner. A few affordable options, a shopping list and clear access to help may be more useful than a long list of restrictions.

Education should also distinguish added sugars from all carbohydrate foods. Fruit, legumes and wholegrains should not be automatically excluded because they contain carbohydrate. Australian dietary guidance encourages food variety while limiting foods and drinks high in added sugars. 

Nourishment is part of success

As a co-founder of UltraLite, I believe practical food knowledge is central to lasting health. The research cited here concerns nutrition and medicines; it does not validate a particular commercial program.

For someone using a GLP-1 medicine, my message is to use the opportunity to learn what supports their body. Ask for help early if eating becomes difficult. A successful plan should make adequate nourishment achievable as appetite changes.

Educational information only. Individual dietary targets, supplements and medication changes should be agreed with your clinician or accredited practising dietitian.

References

1. Friedrichsen M et al. The effect of semaglutide 2.4 mg once weekly on energy intake, appetite, control of eating, and gastric emptying in adults with obesity. Diabetes Obesity and Metabolism. 2021;23:754-762. doi:10.1111/dom.14280. Read the trial.

2. Butsch WS et al. Nutritional deficiencies and muscle loss in adults with type 2 diabetes using GLP-1 receptor agonists. Obesity Pillars. 2025;15:100186. doi:10.1016/j.obpill.2025.100186. Read the observational study.

3. Almandoz JP et al. Nutritional considerations with antiobesity medications. Obesity. 2024;32:1613-1631. doi:10.1002/oby.24067. Read the review.

4. Australian Government. The five food groups. Read the guidance.

5. Mozaffarian D et al. Nutritional priorities to support GLP-1 therapy for obesity. Joint advisory. Obesity. 2025. doi:10.1002/oby.24336. Read the advisory.

6. Australian Government. Australian dietary guidelines 1 to 5. Read the guidance.