Your New Relationship With Food On GLP-1s

Starting a GLP-1 medication is a big step. These medications work by slowing digestion and signalling to your brain that you’re full, which helps reduce your appetite.

In the early weeks, you might notice that food seems to simply matter less. Eating might once have felt urgent or all-consuming, but it can start to feel like an afterthought. This is the medication doing what it’s meant to do.

However, feeling less hungry doesn’t mean your body needs less nourishment. Your muscles still need protein. Your bones, organs, immune system and brain still need vitamins and minerals. Your body still needs enough energy. The medication changes your appetite, but it doesn’t change what your body needs to function properly.

We don’t want to talk about dieting or cutting out certain food groups. Instead, we want to focus on how to fuel your body now that it’s responding to food differently, so that your treatment stays effective and you feel as well as possible along the way.

Article Summary:

• GLP-1 medication changes your appetite, but it doesn’t change what your body needs nutritionally. Eating regularly and well is still essential.
• Old food rules, restriction habits and guilt around eating aren’t part of your treatment journey. This is a chance to build a kinder, more nourishing relationship with food.
• Learning to recognise and trust your new feelings of fullness is important while on GLP-1 treatment.

Leaving old ideas about eating behind

You’ve probably tried a lot of different approaches to eating over the years. Calorie counting. Cutting carbs. Intermittent fasting. Labelling foods as “good” or “bad”. Following strict rules about when, what, and how much you’re allowed to eat.

Many of these habits likely started with good intentions, but a lot of them are based on the idea that willpower and self-control are your main tools. Now that you’re on a GLP-1 medication, that’s no longer the case. You have a powerful new tool helping you.

Some of those old habits can even get in the way of your progress. Skipping meals, eating very little, or cutting out entire food groups can leave you under-fuelled and more likely to experience side effects that are common with GLP-1 treatment, like nausea and fatigue. [1, 2]

What you are aiming for instead

The goal now is a way of eating that feels nourishing, doable, and realistic for your life. That means:

• Eating regularly. Not skipping meals, even if you don’t feel very hungry.
• Including a wide variety of foods. No cutting out entire food groups.
• Focusing on what your body needs, rather than on restriction.
• Paying attention to your body’s new signals, including its changed sense of fullness.
• Letting go of guilt and shame around food.

You don’t need to aim for perfection. You’re aiming for consistency and treating your body with kindness.

What happens when you undereat

Eating too little for too long can lead to:

• Muscle loss, which slows your metabolism and makes it harder to manage your weight over time. [3]
• Fatigue and low energy, which can affect your mood, concentration and motivation.
• Nutritional deficiencies, including low iron, B12, vitamin D, and calcium. [4]
• Worsened nausea. An empty stomach can make this common GLP-1 side effect feel worse.
• A restrictive pattern of eating that’s hard to maintain and may trigger old disordered eating habits.

Eating enough, especially of the right kinds of foods, at regular intervals, is a powerful way to support your medication. Try to think of food as a partner in your treatment rather than something to fight against.

Listening to your body’s new signals

It takes time and practice to notice and trust your new feelings of fullness. A few things that can help:

• Eat slowly. It takes time for your stomach to send “I’m full” signals to your brain.
• Put your fork down between bites so you can pause to check in with how you’re feeling.
• Aim to stop eating when you feel comfortably satisfied, even if there’s still food on your plate.
• Try not to push past that comfortably full feeling. Eating beyond fullness can cause nausea and discomfort.

When portion sizes feel uncomfortably small

It’s normal to worry that your new portions look “too small” or that you’re not eating enough.

But, it’s what is in your portion that matters more than how big it looks. A small meal that includes protein, some vegetables and a slow-releasing carbohydrate is doing a lot of good for your body, even if it looks modest on the plate.

Food, feelings and old patterns

For many people, weight and food aren’t just about the physical side of things. They’re tied up with emotions, too. Years of dieting, food rules, guilt and shame can shape the way we think and feel about eating in ways that don’t help us.

Starting a GLP-1 treatment can bring some of these feelings to the surface. You might notice:

• Relief that appetite has reduced, but also anxiety about whether you’re eating “right”.
• A pull back towards old restrictive habits, such as skipping meals or labelling foods as “bad”.
• Guilt when you eat something that doesn’t fit an imagined “perfect diet”.
• Discomfort or worry around new feelings of fullness, especially if you’ve struggled with overeating in the past.

All of these responses are understandable. They come from years of messaging about food, bodies and weight.

It’s time to gently try a different approach. One where food isn’t the enemy, eating is an act of care, and where the goal is to nourish rather than restrict yourself.

If you notice old disordered eating patterns creeping back in (like restriction, bingeing or feeling guilt about food), please reach out to your GP. Psychological support can make a real difference, and you don’t have to figure this out on your own.

You deserve to eat. Nourishing your body isn’t an obstacle to weight loss treatment, or a lack of willpower. It’s one of the most important things you can do to help your treatment work well.

If you have any questions, the MedExpress clinical team is here to support you.

References

1. Keys A, Brožek J, Henschel A, Mickelsen O, Taylor HL, Simonson E, Skinner AS, Wells SM, Drummond JC, Wilder RM et al (1950) The biology of human starvation NED‐new edition. University of Minnesota Press
2. Fasting and obesity. Br Med J. 1978 Mar 18;1(6114):673. PMID: 630290; PMCID: PMC1603028.
3. Neeland IJ, Linge J, Birkenfeld AL. Changes in lean body mass with glucagon-like peptide-1-based therapies and mitigation strategies. Diabetes Obes Metab. 2024 Sep;26 Suppl 4:16-27. doi: 10.1111/dom.15728. Epub 2024 Jun 27. PMID: 38937282.
4. G Engel M, J Kern H, Brenna JT, H Mitmesser S. Micronutrient Gaps in Three Commercial Weight-Loss Diet Plans. Nutrients. 2018 Jan 20;10(1):108. doi: 10.3390/nu10010108~