Chapter 7 of 11

Nutrition

What your body needs, building balanced meals, avoiding unintentional under-eating, and staying hydrated.

When starting a GLP-1 medication, one of the most noticeable early changes is a shift in appetite. You may feel less hungry, get full more quickly, or find that your usual eating patterns change. Either way, nutrition becomes less about eating less, and more about eating well enough.

Protein — protecting muscle and recovery

Aim for around 1.2–1.6 g/kg/day during active weight loss. Protein helps maintain muscle mass, support metabolism, keep you satisfied, and support recovery and overall health.

Examples include:

  • Meat, poultry, fish
  • Eggs and dairy
  • Tofu, tempeh
  • Beans and lentils

Carbohydrates — your main source of energy

Complex carbohydrates provide slower, more stable energy, and include fibre, which is important for digestion and gut health. Soluble fibre helps with blood sugar and cholesterol; insoluble fibre supports regular bowel movements.

Examples include:

  • Wholegrains (oats, brown rice, quinoa)
  • Starchy vegetables (potatoes, sweet potatoes)
  • Legumes (lentils, chickpeas, beans)
  • Fruits and vegetables

Fats — essential, not something to avoid

Fats play an important role in hormone production, brain function, absorption of key vitamins (A, D, E, K), and overall satisfaction from meals.

Examples include:

  • Olive oil
  • Avocado
  • Nuts and seeds
  • Oily fish like salmon or mackerel

Building your meals

The balanced plate method helps you get a mix of nutrients, even with smaller portions:

  • Have plenty of vegetables and fruits
  • Eat protein-rich foods
  • Choose wholegrain foods
  • Make water your drink of choice

Are you unintentionally undereating?

Because appetite is reduced, it can be easy to under-eat.

This might show up as:

  • Low energy
  • Dizziness or fatigue
  • Difficulty concentrating
  • Rapid weight loss

If this happens, try:

  • Eating smaller meals more regularly (every 2–3 hours)
  • Using protein-based snacks to top up your intake
  • Adding smoothies or softer foods when appetite is low

Hydration

GLP-1 medications slow digestion, and reduced food intake often means less fluid coming in from foods. This can increase the risk of constipation, headaches, fatigue and feeling lightheaded.

You may find it helpful to drink 2–3 litres per day.

Some practical tips:

  • Sip fluids regularly rather than drinking large amounts at once
  • Keep a water bottle nearby as a reminder
  • Include hydrating foods like soups, yoghurt and fruit

Practical ways to get started

If this feels like a lot, you don't need to do everything at once. Start small:

  • Add a source of protein to your meals
  • Include more fibre (e.g. vegetables, beans, wholegrains)
  • Prepare a simple snack for low appetite days
  • Try a smoothie if full meals feel difficult