Protein and muscle on weight-loss medicines: how to protect your strength

Weight-loss medicines reduce appetite strongly. That is how they work. But eating much less, without paying attention to what you eat, can mean losing muscle along with fat. The goal is to lose fat while keeping as much muscle and strength as possible. This page explains why that matters and what usually helps. For background on the medicines, read GLP-1 medicines in India.

Do GLP-1 medicines cause muscle loss?

Any significant weight loss, whether from dieting, surgery or medicines, includes some loss of lean mass. Lean mass includes muscle, but also water, organs and other tissue. In body scans from the semaglutide and tirzepatide trials, a meaningful part of the weight lost was lean mass, with the rest being fat.

There is important nuance. Some of what scans count as “lean” loss may be fat stored inside the muscle, which is actually healthy to lose. Some studies found that muscle quality and physical function stayed the same or even improved as weight came down, although the evidence is still growing. Still, experts agree that protecting muscle is a priority, especially for people who are older, already have low muscle, or are losing weight quickly.

Why does muscle matter so much?

Muscle is more than strength. It:

• helps you walk, climb stairs, carry shopping and avoid falls
• burns energy even at rest, which helps keep weight off
• takes up glucose from the blood, which helps control sugar
• protects bones and joints

Loss of muscle mass and function is called sarcopenia. When sarcopenia and excess fat occur together, it is called sarcopenic obesity, which is common in older Indians and in people with diabetes. It raises the risk of frailty and falls.

How much protein do I need?

Needs vary with your weight, age, activity, kidney health and how fast you are losing weight. Your doctor or dietitian will set a target for you. Expert advice for people on these medicines generally emphasises spreading protein across the day, rather than having most of it at one meal. People with kidney disease need individual advice before increasing protein.

Many Indian diets, especially vegetarian ones, are high in cereals and low in protein. When appetite drops on these medicines, protein often falls even further, because people eat a little roti or rice and skip the dal.

What are good protein sources on an Indian vegetarian diet?

You do not need special supplements to get enough protein. Good everyday sources include:

• Dal and legumes: moong, masoor, toor, chana, rajma, chole and sprouts
• Dairy: paneer, curd, Greek-style hung curd, milk, buttermilk and low-fat cheese
• Soya: tofu, soya chunks and soya milk
• Nuts and seeds: peanuts, almonds, pumpkin and sunflower seeds, in moderate amounts
• Besan and sattu, used in chilla, dhokla or drinks

For non-vegetarians, eggs, fish and chicken are also excellent sources.

Practical tips that many people find useful:

• Start each meal with the protein part first, before rice or roti.
• Add a bowl of curd, a few cubes of paneer or a cup of dal to meals you already eat.
• When appetite is very low, a glass of milk, buttermilk or a soya drink is easier than a full plate.
• Protein powders can help when food alone is not enough. Ask your doctor or dietitian which one is suitable, especially if you have kidney or liver problems.

Why is resistance exercise important?

Protein alone is not enough. Muscle needs a reason to stay. Resistance exercise, which makes your muscles work against a load, is the strongest signal to keep muscle while losing fat. Options include:

• bodyweight exercises such as squats, sitting down and standing up from a chair, wall push-ups and step-ups
• resistance bands at home
• light dumbbells or gym machines, ideally with guidance at first
• yoga poses that hold the body’s weight

Most guidance suggests resistance training on two to three days a week, along with regular walking. Start gently and build up. If you have heart disease, joint problems or are older, ask your doctor what is safe for you.

What else helps?

• Avoid very rapid weight loss. If you are losing weight much faster than expected, tell your doctor.
• Eat enough overall. Very low intake makes muscle loss more likely. Do not skip meals simply because you are not hungry.
• Watch for warning signs: weakness, dizziness, hair fall and feeling cold can mean you are under-eating.
• Check strength, not just weight. Simple tests, such as how easily you stand up from a chair five times, tell your doctor how your muscle is doing. Your waist size also helps track fat loss. Read waist size and health risk.

Muscle and habits also help after treatment. Read stopping GLP-1 medicines and weight regain. For managing low appetite and nausea, see GLP-1 side effects.

What should you ask your doctor?

• What protein target is right for me, given my kidneys and age?
• Should I see a dietitian?
• What type and amount of exercise is safe for me?
• Should my muscle mass or strength be checked during treatment?

A structured plan makes weight loss healthier. Book a consultation to discuss yours.