Up to 39% of weight lost on GLP-1 medications may come from muscle — not fat
Appetite drops. Protein needs don’t.
Weight-loss medications that reduce appetite have helped many people lose weight. However, emerging research suggests that when food intake drops too far, too quickly, a meaningful portion of weight loss may come from lean tissue rather than fat.
A commentary published in The Lancet Diabetes & Endocrinology highlights that medically induced weight loss can be associated with reductions in skeletal muscle mass — particularly when protein intake is insufficient.
This has important implications for how weight loss is supported nutritionally. In some cases, up to 39% of weight lost has been attributed to lean mass, depending on individual factors such as diet quality, total energy intake, and protein consumption.
Why muscle loss matters during weight loss
Skeletal muscle plays a critical role in metabolic health, physical function, and long-term weight maintenance.
Losing muscle alongside fat can make it harder to sustain weight-loss results and may affect strength, energy levels, and blood-sugar regulation over time — particularly as we age.
This is why maintaining adequate protein intake during weight loss is widely recognised as important, especially when overall food intake is reduced.
Knowing protein matters is one thing. Eating enough is another.
For many people using appetite-reducing weight-loss medications, eating enough protein isn’t a conscious choice — it’s a practical challenge.
When appetite is low:
- Meals get smaller
- Solid food can feel unappealing
- Cooking feels like too much effort
- Protein intake often drops without people realising
Over time, this can make it difficult to consistently meet protein needs — even with the best intentions.
A practical way to support protein intake when appetite is low
When appetite is reduced, the goal isn’t to eat more — it’s to make the nutrition you do consume work harder.
For many people, liquid nutrition can be easier to consume than solid meals during low-appetite phases, while still providing meaningful protein.
GlucoBoss is a pharmacist-formulated, simple, high-protein option designed for days when eating a full meal feels like too much.
Each serve provides 30g of protein, with low sugar, in an easy-to-drink format that can fit into a balanced weight-loss approach.
Why shakes can help during low-appetite weight loss
When appetite is reduced, large meals aren’t always realistic — even when nutrition still matters.
Liquid nutrition can offer a practical advantage during these phases. Shakes are often easier to consume than solid food, require minimal preparation, and can deliver a meaningful amount of protein in a smaller volume.
This makes them a useful option for people who are eating less overall, but still want to support muscle maintenance and nutritional adequacy as part of a balanced weight-loss approach.
As with any nutrition strategy, the focus isn’t perfection — it’s consistency.
This article summarises peer-reviewed research and is intended for general educational purposes.
Learn more about GlucoBoss
Prado CM, Purcell SA, Laviano A.
Muscle matters: the effects of medically induced weight loss on skeletal muscle.
The Lancet Diabetes & Endocrinology. 2024.
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