Maybe you have started a GLP-1 medication, or you are weighing it up. Alongside the changes on the scales, you may have seen headlines about muscle loss and wondered what that means for you. The full picture is more reassuring than the headlines, and there is a lot you can do to support your muscles.

What happens as weight comes off

Any weight loss, whether through diet, surgery or medication, includes some fat and some lean tissue. Lean tissue is everything in your body that is not fat. That includes muscle, but also water, organs and bone.

In the main trials of GLP-1 medications, between about a quarter and four in ten of the weight lost was lean tissue. That can sound alarming, but with dieting alone the figure is usually around a fifth to a third, so these medications sit close to the usual range. Only part of that lean tissue is muscle. In one major trial, the proportion of the body made up of lean tissue actually rose, because so much more fat was lost.

Why your muscles still matter

Even so, muscle is worth protecting. It helps you climb stairs, carry shopping and get up from a chair with ease. It supports your joints, and it plays a big part in how your body uses energy.

Muscle also becomes harder to rebuild as we get older. If you spend most of your day at a desk, your muscles may already get fewer chances to work hard. That makes it even more worthwhile to give them a reason to stay.

Eating enough when your appetite is smaller

GLP-1 medications work partly by reducing your appetite. That is helpful for weight loss, but smaller meals can mean you eat less protein, the building block your muscles use to repair and maintain themselves. Research on weight loss more widely suggests that eating enough protein, alongside strength work, helps you hold onto muscle.

Some things to try if you fill up quickly:

• Start each meal with the protein part of your plate.
• Include a source of protein at every meal, such as eggs, Greek yoghurt, fish, chicken, tofu, beans or lentils.
• Choose smaller, more regular meals if large ones feel like too much.
• Keep easy options to hand for busy workdays, like a pot of yoghurt or a handful of nuts.

Staying active alongside treatment

Movement makes a real difference to what your weight loss is made of. In one trial using an earlier GLP-1 medication, people who combined it with a regular exercise programme lost about twice as much body fat as those using either one on its own.

Everyday movement counts. Walking to meetings, taking the stairs and getting up from your desk regularly all keep your muscles working. Strength work sends the most direct signal to your muscles to stay, so it is worth aiming for some on two days a week. It does not need a gym. Rising slowly from your chair without using your hands is a good place to start.

Whether you are starting or still deciding

If you are thinking about a GLP-1 medication, building these habits now gives you a head start. Eating protein regularly and moving more are easier to set up while your appetite and routine feel familiar.

If you are already taking one, it is never too late to begin. Small, steady changes to how you eat and move can help more of the weight you lose come from fat.

What to take away

• Include a source of protein at every meal, and eat it first.
• Choose smaller, regular meals if you fill up quickly.
• Build everyday movement into your working day.
• Aim for some strength work on two days a week.

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