How Much Protein You Need Each Day on a GLP‑1

On a GLP‑1 such as Ozempic, Wegovy, Mounjaro or Zepbound, aim for 1.2 to 1.6 g of protein per kg of body weight a day while you are losing weight. At 70 kg (154 lb), that is 84 to 112 g. A 2025 joint advisory from four US obesity and nutrition societies cites that range (Mozaffarian et al., 2025).

Key facts

• The 2025–2030 Dietary Guidelines for Americans give the same range as the protein goal for all adults, adjusted for calorie needs (USDA and HHS, 2026).
• Reference intakes for healthy adults are lower: 0.75 g/kg in the UK, 0.8 in the US and 0.83 from EFSA (Morris et al., 2020; Mozaffarian et al., 2025; EFSA, 2012).
• The advisory sets a floor of 0.4 to 0.5 g/kg a day and says to avoid more than 2 g/kg for long periods (Mozaffarian et al., 2025).
• Over 65, the PROT-AGE group recommends at least 1.0 to 1.2 g/kg a day (Bauer et al., 2013).
• In obesity, the advisory offers 1.2 to 2.0 g/kg of adjusted weight, 1.5 g/kg of fat-free mass or 80 to 120 g flat as alternatives (Mozaffarian et al., 2025).

How much protein on a GLP‑1, by situation

Each row gives a daily figure, who it is for and who set it, with a link to a source that states it.

The GLP‑1 protein calculator multiplies your own weight by the weight-loss range and splits the total into meals. At 70 kg, 84 to 112 g a day is 21 to 28 g at each of four meals (84 ÷ 4 and 112 ÷ 4).

Rather than setting the weight-loss range itself, the advisory reports that targets "such as 1.2–1.6 g/kg body weight/day" have "also been proposed" during active weight loss (Mozaffarian et al., 2025). For all US adults, the 2025–2030 Dietary Guidelines set 1.2 to 1.6 g/kg as a goal, "adjusting as needed" for calorie needs (USDA and HHS, 2026).

The lower reference intakes are for healthy adults in general. EFSA’s 0.83 g/kg comes from nitrogen-balance studies and applies at all adult ages (EFSA, 2012). The UK’s 0.75 g/kg dates from the 1991 Dietary Reference Values (Morris et al., 2020; SACN, 2025). For adults aged 19 to 64 it works out at 55.5 g a day for men and 45.0 g for women (Public Health England, 2016). The UK Scientific Advisory Committee on Nutrition says it will review protein as part of its future work program (SACN, 2025).

Over 65, PROT-AGE recommends 1.2 g/kg or more for people who exercise, and 1.2 to 1.5 g/kg for older adults with an acute or chronic illness (Bauer et al., 2013).

Actual, adjusted or ideal body weight

For people with obesity, the advisory says it is unclear which body weight protein targets should use, and that actual weight "can significantly overestimate protein requirements" (Mozaffarian et al., 2025). It names adjusted body weight as one basis but publishes no formula for it. The alternatives it lists are:

• 1.2 to 2.0 g/kg of adjusted body weight a day in major weight loss
• a flat 80 to 120 g a day, which it says may be easier to stick to
• 1.5 g per kg of fat-free mass a day, which needs a body-composition measurement

At 120 kg, multiplying actual weight gives 144 to 192 g a day (120 × 1.2 and 120 × 1.6), well above the flat 80 to 120 g. At 70 kg, the 84 to 112 g already sits inside the flat range.

A dietitian may give you an ideal or adjusted weight to use; enter that figure in the protein calculator in place of your own. For an ideal weight, put your height into the GLP‑1 goal weight calculator, which applies the classic formulas.

A small 2025 study looked at 60 adults using a GLP‑1 medicine for weight loss (Johnson et al., 2025). Against adjusted body weight, their 3-day food records showed 43% reaching 1.2 g/kg a day and 10% reaching 1.6 g/kg (Johnson et al., 2025).

Upper and lower limits

Below 0.4 to 0.5 g/kg a day, intake can lead to muscle atrophy and functional impairment (Mozaffarian et al., 2025). At the top end, the joint advisory warns against prolonged intake above 2 g/kg a day, citing potential adverse health effects (Mozaffarian et al., 2025).

A 2018 meta-analysis of 49 trials with 1,863 healthy adults doing resistance training found no further gain in fat-free mass once total protein intake passed 1.62 g/kg a day (Morton et al., 2018). None of those trials involved GLP‑1 medicines, and they measured mass gained while training.

The International Society of Sports Nutrition calls 1.4 to 2.0 g/kg a day "sufficient for most exercising individuals" in its 2017 position stand (Jäger et al., 2017). For resistance-trained people eating in a calorie deficit, it says 2.3 to 3.1 g/kg may be needed to keep lean mass, above the advisory’s 2 g/kg limit (Jäger et al., 2017).

Why protein matters during GLP‑1 weight loss

Trial scans put 25 to 39% of the weight lost down to lean mass, the 39% being STEP 1’s 5.3 of 13.6 kg on semaglutide (Look et al., 2025; Mozaffarian et al., 2025).

In the advisory’s words, "increased protein intake alone is likely inadequate to support the preservation of muscle mass in the absence of structured resistance/strength training" (Mozaffarian et al., 2025). It pairs GLP‑1 treatment with strength training at least 3 times a week and at least 150 minutes of moderate aerobic exercise a week (Mozaffarian et al., 2025).

Excessive hair loss is on the advisory’s list of signs of nutrient deficiency in people taking GLP‑1s (Mozaffarian et al., 2025). In the trials behind the UK licence, hair loss on Mounjaro was reported by 4.9% of people on tirzepatide, against 1.0% on placebo (Mounjaro SmPC, section 4.8).

One range for every GLP‑1

The joint advisory uses "GLP‑1s" for semaglutide, liraglutide and tirzepatide alike, and none of its protein figures changes with the brand or the dose (Mozaffarian et al., 2025). The 1.2 to 1.6 g/kg range holds on Ozempic or Wegovy (semaglutide) and on Mounjaro or Zepbound (tirzepatide), from the first dose step to the last.