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Lean mass: you lose lean and regain fat

Six to seven kilograms of lean mass goes during treatment. About 5.6 kg comes back after stopping, preferentially as fat. The scale can read the same either way.

Glenn Torres6 min read
What comes off, and what comes backon treatmentfat and 6–7 kg of lean massafter stopping5.6 kg back, preferentially fatThe same weight, made of different tissue.Figures gathered by a narrative review, not measured in it.

Weight coming back after stopping is well established and covered elsewhere on this site. This review is about something narrower and less discussed: what the returning weight is made of.

What it gathers

A narrative review searching three databases from 2005 to mid-2026, assembled under a standard framework for this kind of review. [1] Every number in it is drawn from other studies rather than measured, and a narrative review chooses what to include — so these are figures it found, presented as it read them.

On treatment, lean mass fell by 6 to 7 kg on average, alongside reductions in bone mineral density. After stopping, weight rose by 5.6 kg on average within one year, described as fat-preferential, with observational reports of dose-dependent cardiometabolic worsening.

The persistence figure

The review cites 85% of patients discontinuing within the second year of real-world use, which is the premise of the whole paper: if most people stop, what happens after stopping is most of the story.

That figure comes from the literature the review surveys rather than from its own data, and persistence estimates vary considerably depending on how long a gap counts as stopping. The direction is not in dispute; the exact number should not be quoted as though it were measured here, any more than a multiplier quoted without its base should.

What it recommends, and what this page will not

Structured exercise, on the grounds that exercise and pharmacotherapy produce fundamentally different body composition outcomes — exercise preserving lean mass where the drug does not.

The review offers prescription guidance. This page does not, because what is appropriate depends on age, joints, cardiac fitness and what somebody is already doing. What is safe to say is that the cessation transition currently has no established framework, the authors say so, and nobody selling a subscription is planning one — it is not among the things sellers publish.

Frequently asked

Is the weight that comes back the same as the weight that went?
Not according to this review. Lean mass losses of 6 to 7 kg occur during treatment, while post-cessation regain averaging 5.6 kg is described as fat-preferential.
Why does that matter if the scale reads the same?
Because lean mass drives resting energy expenditure. Ending a cycle with less muscle and more fat than you started with makes the next attempt harder.
How many people stop?
The review cites 85% discontinuing within the second year of real-world use, drawn from the literature it surveys rather than measured in it.
What should somebody do about it?
The review argues for structured exercise, since exercise preserves lean mass where the drug does not. What is appropriate for a particular person is a clinical question.

Sources

  1. [1] Zeigler Z, et al. (2026). Structured Exercise During and After Incretin-Based Pharmacotherapy Discontinuation: A Narrative Review of Mechanisms, Evidence, and Prescription Guidance Healthcare. PMID 42588312

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