Nutrition and Lifestyle Support During GLP-1 Therapy

Written By Kathryn Stevenson
GLP-1 Therapy, nutrition, weight loss

How to support your health while taking GLP-1 weight loss medications

GLP-1 medications have transformed the treatment of obesity and weight management. For many people who have struggled with their weight for years, these medications can help reduce appetite, quieten constant “food noise,” and support meaningful weight loss.

However, while GLP-1 therapy can be highly effective, it’s important to understand that these medications are only one part of the picture. Without the right nutrition and lifestyle support, people can experience muscle loss, nutrient deficiencies, digestive issues, and reduced bone health during treatment.

The goal should not simply be weight loss — it should be improving your overall health and wellbeing while protecting your body along the way.

How GLP-1 Medications Work

GLP-1 medications mimic a natural hormone released after eating. They work by:

  • Slowing stomach emptying

  • Helping you feel fuller for longer

  • Reducing appetite and cravings

  • Supporting blood sugar regulation by increasing insulin release

These effects help reduce calorie intake, but they can also unintentionally reduce overall nutrient intake, making nutrition quality especially important.

Common Side Effects

Some people may experience side effects such as:

  • Nausea

  • Constipation

  • Diarrhoea

  • Occasional vomiting

  • Headaches

  • Early fullness

  • Food aversions

If symptoms are persistent or severe — particularly severe abdominal pain or ongoing vomiting — seek medical advice promptly.

Why Nutrition Matters on GLP-1 Therapy

Because appetite is reduced, many people eat significantly less while taking GLP-1 medications. While this supports weight loss, it can also increase the risk of nutrient deficiencies and loss of lean muscle mass if meals are not carefully planned.  Some commonly affected nutrients include:

Key Nutrients at Risk

  • Protein

  • Fibre

  • Magnesium

  • Iron

  • Zinc

  • Calcium

  • Vitamin D

  • Vitamin B12

  • Folate

  • Thiamine (Vitamin B1)

Low intake of these nutrients may contribute to:

  • Muscle loss

  • Fatigue and low energy

  • Poor recovery

  • Reduced bone density

  • Constipation

  • Reduced immune function

Prioritise Muscle, Gut & Bone Health

There are a number of factors to consider when planning meals whilst taking GLP-1s.  A Mediterranean style diet with the emphasis on whole grains, vegetables, nuts, olive oil, seafood, oily fish, chicken and limited red meat, is a well-researched dietary style and is recommended for people undergoing GLP-1 therapy.

When planning your meals, think protein first, then fibre (vegetables, salad, and some fruit) and only add carbohydrates if you are still hungry.  This may take a little time to adjust to, however it will ensure that you are prioritising muscle and gut health.  The main considerations are:

1. Focus on Protein First

One of the biggest risks during rapid weight loss is losing muscle mass alongside body fat.  Protein helps:

  • Preserve muscle

  • Support metabolism

  • Improve fullness

  • Aid recovery and strength

  • Aim to include a quality protein source at every meal, such as:

  • Fish

  • Chicken

  • Eggs

  • Lean red meat

  • Greek yoghurt

  • Tofu or tempeh

  • Legumes

  • Nuts and seeds

The recommendation for protein consumption is to aim for approximately 1.0–1.5g of protein per kilogram of body weight daily, depending on activity levels and individual needs.  Contact your Clinical Nutritionist who will be able to help with calculating the ideal amount for you and your lifestyle.

2. Add Some Fibre

The Australian recommendation for daily fibre intake is:

  • 25 grams per day for women

  • 30 grams per day for men. 

This should be considered the minimum amount of fibre you need to eat for healthy digestion and microbiome.  Fibre is essential for:

  • Healthy bowel movements (constipation is one of the most common complaints during GLP-1 therapy):

  • Feeding beneficial gut bacteria

  • Supporting heart and metabolic health

  • Improving fullness and blood sugar balance

Aim to include a wide variety of colourful plant foods every day, including:

  • Leafy greens

  • Berries

  • Apples

  • Tomatoes

  • Pumpkin

  • Sweet potato

  • Garlic and onions

  • Beans and legumes

3. Stay Hydrated

GLP-1 medications can increase the risk of dehydration, especially if nausea or constipation are present.  Aim for:

  • 2–3 litres of fluid daily

  • Mostly water

  • Water-rich foods like cucumber, soups, and watermelon

Try to minimise:

  • Sugary drinks

  • Excess alcohol

  • Too much caffeine

Good hydration supports digestion, energy, mood, and bowel regularity.

4. Include Healthy Fats

Healthy fats support hormone production, brain health, and nutrient absorption.  Include foods such as:

  • Extra virgin olive oil

  • Avocado

  • Nuts and seeds

  • Oily fish like salmon or sardines

The Importance of Exercise

Exercise is one of the most important tools for protecting your health while losing weight.

Strength Training

Weight bearing exercise not only helps to build muscle, but it also helps to improve bone density and protect against osteoporosis.  Aim for:

  • 2 sessions per week of 30 minutes per session.  Strength training includes weight training at a gym or at home, using free weights, weight machines, body weight or a resistance band.

Aerobic Exercise

Regular movement supports cardiovascular health, energy, and mood. Aim for:

  • 150 minutes of moderate intensity exercise per week split into daily sessions, like walking at a moderate pace, or 75 minutes of vigorous intensity exercise per week.

Don’t Forget Mental Wellbeing

Weight loss journeys can be emotional as well as physical. Supporting your nervous system and managing stress can improve your overall experience and long-term success. Helpful practices may include:

  • Meditation

  • Yoga

  • Deep breathing

  • Walking in nature

  • Journalling

  • Spending time with family and friends

Personalised Support Makes a Difference

GLP-1 therapy works best when combined with personalised nutrition and lifestyle guidance.  A Clinical Nutritionist can help:

  • Monitor nutrient intake

  • Support gut health

  • Preserve muscle mass

  • Reduce side effects

  • Create sustainable eating habits

  • Support long-term health outcomes

The aim is not only to lose weight, but to come out of therapy healthier, stronger, and feeling your best.

Written by:  Kathryn Stevenson, BHSc (Clinical Nutrition)

*References available on request.

Kathryn Stevenson
Previous

Is this Perimenopause? Understanding Perimenopause and the Stages Beyond
Next

The Clinical Importance of Functional Testing