How Much Protein Do You Need to Keep Muscle?

Updated October 24, 2026 · By the DEXASCAN.COM Team

Key takeaways

• The old baseline of 0.8 g/kg (0.36 g per pound) is a minimum, not a muscle-building target.
• The 2025–2030 Dietary Guidelines, released January 7, 2026, set a target of 1.2–1.6 g/kg per day and say to prioritize protein at every meal.
• Research suggests muscle gains from extra protein level off around 1.6 g/kg per day, so "1 gram per pound" is more than most people need.
• Protein works best with resistance training, and a DEXA scan is how you see whether it's working.
• DEXA, VO2 Max and RMR testing start at $89 on DEXASCAN.COM.

Protein is having a moment. When the federal government released the 2025–2030 Dietary Guidelines for Americans on January 7, 2026, one of the headline changes was a higher daily protein target than earlier federal guidance. Add the many people on GLP-1 medications worried about losing muscle, and "how much protein do I actually need?" is suddenly everywhere. Here's what the research says and how to check that it's working.

How much protein do you need per day to keep muscle?

For most adults who want to keep or build muscle, a practical target is 1.2 to 1.6 grams of protein per kilogram of body weight per day. That's the range the 2025–2030 Dietary Guidelines recommend, alongside "prioritizing protein foods at every meal."

To convert to pounds, multiply your weight in pounds by about 0.55 (low end) and 0.73 (high end). For a 140-pound person, that works out to roughly 76 to 102 grams a day.

Compare that with the Recommended Dietary Allowance (RDA) of 0.8 g/kg, or 0.36 grams per pound. As Harvard Health explains, that RDA translates to about 53 grams a day for a 140-pound, 50-year-old woman. The RDA covers basic needs; it isn't a muscle-building target.

Is 1 gram of protein per pound too much?

For most people, yes, it's more than they need. One gram per pound equals about 2.2 g/kg, which is above the level where research shows benefits flatten out.

A 2018 meta-analysis in the British Journal of Sports Medicine, led by Robert Morton at McMaster University, pooled 49 randomized trials with 1,863 participants who lifted weights. Protein supplementation significantly improved muscle size and strength, but the benefit plateaued at roughly 1.6 g/kg of body weight per day. The researchers also found:

• Effects were similar in women, and protein source and timing didn't change results.
• The effect of protein supplementation got smaller with age, suggesting older adults may need more to get the same benefit.

So "1 gram per pound" isn't necessary for most people, and those extra grams still carry calories.

How much protein should you eat on a GLP-1 like Ozempic or Mounjaro?

During active weight loss, higher protein targets of 1.2 to 1.6 g/kg per day have been proposed, along with a simple absolute target of 80 to 120 grams a day. Both come from a 2025 joint advisory published in the journal Obesity by the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association and The Obesity Society.

The same advisory describes a target it considers more accurate: 1.5 grams per kilogram of lean body mass (fat-free mass) per day. For someone with 50 kg of lean mass, that's about 75 grams a day. You can only calculate that number if you know your lean mass, which is exactly what a DEXA scan measures.

Why it matters: the advisory notes that in the STEP 1 semaglutide trial, 5.3 kg, or 38% of the weight lost, was lean body mass, and it estimates that roughly 20% of total weight reduction was muscle. It also cautions that "increased protein intake alone is likely inadequate" to preserve muscle, which is why resistance training belongs in the plan. Our recent post on new 2026 research on GLP-1 muscle loss goes deeper on those numbers.

How do you know if your protein intake is actually working?

Measure your muscle, not just your weight. The scale can't tell you whether a pound lost was fat or muscle.

A DEXA scan (dual-energy X-ray absorptiometry) is a low-dose X-ray body composition scan that takes about 10 minutes while you lie still on a padded table. It shows:

• Body fat percentage and total fat mass
• Lean muscle by region (each arm, each leg and your trunk), so you can see where you're gaining or losing
• Visceral fat, the deeper fat packed around your organs that is linked to cardiometabolic risk
• Bone density
• ALMI (appendicular lean mass index), your arm and leg lean mass adjusted for height, a key marker for healthy aging

If your lean mass is holding steady or rising while fat comes down, your protein and training are doing their job. If it's dropping, revisit your intake and lifting with your provider or coach. Our guide to ALMI and what it predicts about aging explains how to read that number, and why a DEXA scan may say you lost muscle covers the common reasons results shift between scans. You can also learn more about DEXA body composition testing.

What to do next

1. Pick your number. Start with 1.2–1.6 g/kg of body weight, or 1.5 g/kg of lean mass once you know it from a DEXA scan.
2. Spread it out. Build each meal around a protein food.
3. Lift. Regular resistance training gives that protein a reason to become muscle.
4. Talk with your provider before big changes, especially with kidney disease.
5. Get a baseline DEXA scan, then rescan every 8–12 weeks at the same location so you're comparing apples to apples.

For a full game plan on cutting fat while protecting lean mass, read Lose Fat, Not Muscle in 2026.

Frequently asked questions

How much protein do I need per day to keep muscle?

Most active adults trying to keep or build muscle do well at about 1.2 to 1.6 grams of protein per kilogram of body weight per day, the range in the 2025–2030 Dietary Guidelines for Americans. That is roughly 0.55 to 0.73 grams per pound, paired with resistance training.

Is 1 gram of protein per pound too much?

For most people, 1 gram per pound (about 2.2 g/kg) is more than the research shows is needed for muscle growth. A 2018 meta-analysis in the British Journal of Sports Medicine found gains from protein leveled off at roughly 1.6 g/kg per day.

How much protein should I eat on Ozempic or Mounjaro?

A 2025 joint advisory from four medical and nutrition societies, published in Obesity, noted that targets of 1.2 to 1.6 g/kg per day have been proposed during active weight loss, and suggested an absolute target of 80 to 120 grams per day may be easier to follow. Ask your prescriber or dietitian for a target that fits your health history.

How much does a DEXA scan cost?

Prices vary by location and provider. On DEXASCAN.COM, DEXA, VO2 Max and RMR testing start at $89, with prices shown upfront before you buy.

How often should I get a DEXA scan to track muscle?

Every 8 to 12 weeks is a practical interval for tracking changes from a new diet, training program or medication. Use the same location so your results are comparable.

Related reading

• New 2026 Research: Up to a Third of GLP-1 Weight Loss Can Be Muscle
• Why Did My DEXA Scan Say I Lost Muscle?
• What Does a DEXA Scan Actually Measure?

Find a DEXA scan near you

DEXASCAN.COM validates its providers, shows prices upfront, and lets you buy online and get booking instructions within minutes. DEXA, VO2 Max and RMR testing start at $89, and you can bundle all three with the Big 3 testing package.

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Sources: Morrison Foerster, "New U.S. Dietary Guidelines Released" (Jan. 2026); American Family Physician, "Dietary Guidelines for 2025–2030" (2026); Harvard Health Publishing, "How much protein do you need every day?"; McMaster University, "How to build whey more muscle" (on Morton et al., British Journal of Sports Medicine, 2018); Nutritional priorities to support GLP-1 therapy for obesity: a joint advisory, Obesity (2025).

This article is for educational purposes and is not medical advice. Talk with your healthcare provider before starting or changing any medication, diet or exercise program.