The trials that made these medicines famous measured weight, blood sugar and hearts. Almost none of them measured what anyone ate. The guidance has been catching up ever since, and a consensus statement published online in November 2025 is the most complete attempt so far.
What happened
An international, multidisciplinary panel of physicians, clinical researchers and dietitians agreed a set of nutritional and lifestyle supportive care recommendations for managing obesity with GLP-1 based therapies. It was built through a modified Delphi process, where a panel votes in rounds until it converges, over a scoping review of the literature from January 2021 to June 2025.
The statement appeared online on 11 November 2025 and in the March 2026 issue of Obesity Pillars (PubMed 41502845).
The numbers worth carrying
Two figures do most of the work.
During rapid weight loss, the panel puts protein at 1.2 to 1.5 g per kg of actual body weight a day, or around 25 to 30% of energy on a 1,600 kcal day, alongside keeping physical activity up, specifically to protect muscle, and especially in older people or anyone at risk of sarcopenia.
For major weight reduction, the recommendation is expressed against adjusted body weight rather than actual weight, at 1.2 to 2.0 g per kg a day. The panel also sets a floor: intake should not fall below 0.4 to 0.5 g per kg a day, because below that you get muscle atrophy and loss of function.
Adjusted body weight is the detail that trips people up. For someone well above a healthy weight, calculating protein from actual weight gives a number nobody can eat on a quiet appetite, and calculating it from ideal weight gives one that is too low to protect muscle. Adjusted body weight sits between the two, and it is the basis this site uses for the same reason.
Why a consensus statement, rather than a trial
It is worth being honest about what this is. A Delphi panel is expert agreement, not new evidence. It is what a field does when clinicians need an answer before the trials exist, and it sits below a randomised trial and above an opinion piece.
That is the right tool here, because the underlying question is not going to be answered by a trial any time soon. This is also the second such document in a year: a joint advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association and The Obesity Society landed in 2025 (PubMed 40445127) and reached compatible conclusions. When two independent panels converge, the agreement carries more weight than either alone.
What it means for you
Take one number to your next appointment: the grams of protein a day your weight and your stage call for. It is a concrete question with a concrete answer, and it moves a conversation along faster than "am I eating enough?".
Then check it against what you actually ate yesterday rather than what you intend to eat tomorrow. On a quiet appetite the gap between the two is usually where the muscle goes.
What to do with this
Your protein floor is built from adjusted body weight and your dose, which is exactly the method these panels describe. The calculator does that arithmetic.