Comment développer la masse musculaire après un traitement de perte de poids

How does weight loss treatment affect muscle mass?

Weight loss treatments - such as injections - work by reducing your appetite, helping you feel fuller for longer, or limiting how much fat your body absorbs. If you’re using these treatments, you’ll likely notice faster results compared to conventional methods of weight loss. The same applies to those who undergo weight loss (bariatric) surgery.

While losing weight quickly might seem appealing, it isn’t always ideal for your muscles. When your body sheds weight too fast, it may break down muscle tissue for energy, as it's easier to access than fat. This can lead to a loss of muscle strength, which is why it’s especially important to focus on supporting and reinforcing your muscle health during periods of accelerated weight loss.

Helen O'Leary, physiotherapist and clinical Pilates expert, Complete Pilates, London, UK explains that many people who are on the weight loss injection Ozempic - for example - will lose around 5-10% of their body weight within the first year.

“Weight loss obviously comes with lots of health benefits,” she says. “But losing weight very rapidly can also reduce your muscle mass and bone density as well as lower your resting metabolic rate.”

How to start building muscle after weight loss

Once your initial weight loss treatment has stabilised and you’ve been cleared by a medical professional, you can begin incorporating a muscle-building routine into your daily schedule.

O’Leary emphasises that it’s crucial to discuss exercise with your healthcare provider from the very beginning of your weight loss treatment plan.

“They will be able to factor this into decision-making and ensure they tell you when it is appropriate to start,” she says.

Building muscle with resistance and strength training

O’Leary suggests focusing on resistance and strength training as the most effective forms of exercise during weight loss interventions. These exercises help you maintain your muscle mass while boosting your metabolism, so you burn more calories - even when you’re at rest.

“Within resistance training, you need to ensure that you are giving yourself adequate rest periods - not just between sets but between workouts,” she says. “This will ensure appropriate recovery time for your muscles to recover and grow. Depending on your starting level, the resistance can be body weight, dumbbells, or using equipment such as in a Pilates studio.

“Start with gentle strength training two or three times a week to allow for muscle recovery and growth.”

What to eat for muscle growth and recovery

O’Leary proposes that, in addition to a fitness professional, you should consider working with a dietitian to make sure you’re getting the right amount of calories and protein for your individual needs.

Helena Barham is a London-based nutritional therapist and founder of Nourish&Be. She points out that the recommended protein intake is 0.75 grams per kilogram of body weight per day. In simpler terms, if you weigh 70 kilograms, you should aim for at least 60 grams of protein daily.

“Protein is really important for muscle building, as well as supporting connective tissue,” Barham explains. “If your goal is to build muscle, you might want to aim for 1-1.2 kilograms of protein a day.”

She cautions that exceeding this amount can be harmful, placing extra strain on your body’s sensitive organs - such as the kidneys. For this reason, she rarely recommends relying on supplements such as protein powders.

Barham also highlights these additional nutrients to support muscle building:

• Vitamine C - to support collagen synthesis, found in kiwis, blackcurrants, oranges, strawberries, broccoli.

• Magnésium - for muscle function and relaxation, found in pumpkin and sunflower seeds, spinach, kale, dark chocolate.

• Zinc - for protein synthesis, found in oysters, graines de citrouille, cashews, dark chocolate.

• Vitamine D - for muscle contraction and supporting bone health, found in eggs, mushrooms, fish. In the UK, the NHS advises taking a daily vitamin D supplement during the months from October to March.

• A variety of B vitamins - found in eggs, fermented dairy, leafy green vegetables, such as spinach, and kale, nuts and seeds, nutritional yeast.

“Consider a good quality wholefood multivitamin if you are really keen to take something - but always try to get nutrients from your diet first,” she adds. “And please do not underestimate the importance of rest and recovery - not doing so is a fast track to hormone dysregulation.”

What is body recomposition?

Body recomposition happens when you shed fat and gain muscle at the same time.

O’Leary explains that this process is usually achieved through a programme of targeted exercise and diet.

“In general, strength training will help you build muscle, cardio will help reduce fat, and eating enough protein - while maintaining a slight calorie deficit - supports both goals,” she says.

“It is important to understand that this is a slower process than traditional weight loss, so consistency in your training and diet is key to achieving it. This is a great tool for beginners, older adults, or those with overweight.”

Barham describes body recomposition as a somewhat problematic practice.

“This supposedly simple maths of burning more calories than you eat just doesn’t work for long,” she says. “The reason why, is that your body gets used to the low calorie intake, so it resets your metabolism at a lower rate - thus halting weight loss.”

She advises that bulking, enjoying treats and feast meals, and taking rest days are essential for signalling to your metabolism that it’s safe to maintain its normal pace.