Glucagon-like peptide-1 (GLP-1) drugs facilitate weight loss by stimulating insulin secretion, delaying emptying of the stomach contents and reducing hunger.
While the development of GLP-1 agonists has triggered a new era in weight management, concerns have arisen that they may cause an accompanying loss of muscle mass and function (common in old age as sarcopenia) – associated with impaired physical function, reduced quality of life and increased risk of falls, illness and death.
US and obesity medicine specialist Dr Christopher McGowan told medicalnewstoday.com: ‘Losing weight at the expense of lean muscle can lead to future problems, including reduced basal metabolic rate, decreased strength, fitness and tone, reduced bone density, and an increased risk of weight recurrence. For these reasons, it is essential to prioritise muscle preservation.’
Research suggests that consuming a protein-rich diet and regular exercise; even a moderate increase in protein consumption can help preserving muscle on GLP-1 drugs for weight loss patients. Supplementation with whey protein and essential amino acids can also help meet the desired daily protein intake and facilitate muscle protein synthesis.
US obesity medicine expert Dr Meghan Garcia-Webb suggested: ‘A good goal is to aim for 1.0-1.2 grams of protein per kilogram, which is the ideal protein intake per body weight daily. So for someone who wanted to weigh 150lbs (68kg), getting around 70-80 grams of protein daily would be a good goal.’
But Dr McGowan also warned: ‘GLP-1 medications can make you feel sick. If you are nauseous, bloated or uncomfortable, you are more likely to choose less nutritious, easier-to-digest foods, often low in protein. If medication side effects prevent you from reaching your nutrition goals, the dosage may need to be adjusted.
‘Working closely with a registered dietitian can provide valuable insight and a customised nutrition plan, while tracking intake can ensure one meets these recommended goals.’
Endurance and resistance or weight training are effective in slowing down muscle loss accompanying weight loss; resistance training can also increase muscle strength and improve physical function due to increased protein synthesis in the muscles and their composition.
Dr Garcia-Webb emphasised: ‘Strength training is very important to anyone starting a GLP-1 agonist medication. I advise training at least twice per week for 30 minutes. If a patient is brand new to resistance training, I always recommend meeting with a trainer once or twice to make sure they know how heavy they should lift and that they are maintaining proper form.’
Cornell University’s Professor Beverly Tchang agreed that ‘people at risk of frailty or sarcopenia and taking a GLP-1 drug should be more mindful of incorporating resistance training to mitigate lean mass loss’.
Dr McGowan summed up: ‘The key to healthy, sustainable weight loss is maintaining protein intake and nutrition, performing regular resistance exercise, and staying consistent.’
