How Much Protein Should You Eat on a GLP-1 Medication?

There is no single agreed number, but there is a sensible range. In 2025, four US organizations in nutrition, lifestyle medicine and obesity published a joint advisory on nutrition for people taking GLP-1 medications for obesity. Its main protein points are:

• The recommended dietary allowance (RDA) is 0.8 g per kg of body weight a day. That is a minimum to prevent deficiency, not an optimum ^[1].
• Higher targets of 1.2–1.6 g/kg a day have been proposed during active weight loss ^[1]. That is roughly 0.5–0.7 g per lb.
• Intake should not fall below 0.4–0.5 g/kg a day, and prolonged intakes at or above 2 g/kg a day should be avoided ^[1].
• A practical alternative is a fixed target of 80–120 g a day ^[1].

For many people on Ozempic® or Wegovy® (semaglutide) or Mounjaro® or Zepbound® (tirzepatide), the hard part is not knowing the number. It is reaching it when you are rarely hungry. Research looking at people using these medicines suggests protein intake often falls short of what a lower-calorie diet calls for ^[6].

GLP-1 medications reduce appetite. That helps with weight loss, but it can also shrink your protein intake without you noticing.

At the same time, some of any large weight loss is lean mass. In the STEP 1 semaglutide trial's body scan sub-study, about 5.3 kg (12 lb) of the average 13.6 kg (30 lb) lost was lean mass ^[1]. Lean mass includes muscle, but also water, organs and connective tissue, so not all of that was muscle. The full results are in does Ozempic cause muscle loss?

Protein does not protect muscle on its own. It works best alongside strength training, which the joint advisory recommends at least 3 times a week for people on GLP-1 medication ^[1].

Protein guidelines are written in grams per kilogram of body weight. If you multiply a g/kg target by a high body weight, you can end up with a number that is very hard to eat, because body fat needs far less protein to maintain than muscle does.

The joint advisory is open about this. It says it is uncertain whether targets should be based on actual body weight, an adjusted or ideal body weight, or fat-free mass ^[1].

Our protein calculator takes a conservative middle path used in clinical nutrition practice ^[5]:

• BMI under 30: it uses your actual weight.
• BMI 30 or above: it uses an adjusted body weight. This starts from your ideal body weight and adds back only part of the weight above it.

Ideal body weight comes from the Devine formula: 50 kg for men or 45.5 kg for women, plus 2.3 kg for every inch (2.54 cm) of height over 5 feet (152.4 cm) ^[4]. If you choose "prefer not to say" for sex, the calculator uses the more conservative female formula.

Some sports nutrition guidance uses fat-free mass instead, suggesting 2.3–3.1 g per kg of fat-free mass for resistance-trained people eating in a calorie deficit ^[2]. That needs an accurate body composition measurement. Home smart scales are not precise enough for it, so the calculator does not use this method.

The calculator gives you a range rather than one number. Ranges are grams per kg of reference weight, which means your actual weight, or your adjusted weight if your BMI is 30 or above.

Two extra rules keep the output safe:

• Age 65 and over: the low end of the range is at least 1.0 g/kg, in line with expert guidance for older adults ^[3].
• Ceiling: the top of the range never goes above 2.0 g/kg, matching the advisory's caution about prolonged intakes at or above that level ^[1]. The daily total is capped as well.

The advisory's simpler target of 80–120 g a day ^[1] is a useful sanity check on whatever number you land on.

Here is how the calculator handles an example person:

• Woman, 168 cm (5 ft 6 in), 105 kg (231 lb), BMI 37.2
• Taking tirzepatide and losing weight
• Strength training twice a week

Step 1: reference weight. Her BMI is above 30, so the calculator uses adjusted body weight. Her Devine ideal body weight is about 59.6 kg (131 lb) ^[4]. Adding back part of the weight above that gives an adjusted weight of about 77.8 kg (172 lb).

Step 2: range. She is losing weight and strength training, so her range is 1.4–1.8 g/kg ^{[1] [2]}. Applied to 77.8 kg, that comes to about 109–140 g a day.

Step 3: split. Across 5 small meals, that is about 22–28 g of protein at each.

If the calculator had used her full weight of 105 kg, the range would have been 147–189 g a day. That is a lot of food for someone with a reduced appetite, and it is the reason the adjustment matters.

Low appetite, nausea and feeling full quickly are common reasons people fall short. The joint advisory's practical suggestions are:

• Eat a small breakfast, then small meals every 3–4 hours, while drinking enough fluids ^[1].
• Put protein first at each eating occasion ^[1].
• Smaller, more frequent meals and avoiding fatty or high-fiber foods during the first few days of treatment can help ^[1].

Sports nutrition research suggests about 20–40 g of protein per meal, or roughly 0.25 g per kg of body weight, is an effective amount ^[2]. Guidance for older adults also favors spreading protein across meals rather than saving it for one large dinner ^[3].

So splitting your target into 4 or 5 smaller meals works well. For example, 120 g a day becomes 24 g across 5 meals, or 30 g across 4. If a meal would fall below about 20 g ^[2], a protein-dense snack or a shake can top it up.

If you cannot keep food or fluids down, or nausea stops you eating most days, talk to your prescriber. Do not change how you take your medication without their advice.

These portions give roughly 20–30 g of protein. Values are approximate and vary by brand and preparation, so check the label.

Cold, soft or liquid options such as yogurt, cottage cheese and shakes may be easier to manage on days when you feel queasy.

Before you use the calculator

These ranges are for healthy adults. They are not meant for under-18s, pregnancy or breastfeeding, people with kidney or liver disease, or anyone with a history of eating disorders unless they are supervised. If any of those apply to you, get a protein target from your care team.

Use the protein calculator to get your own range and per-meal split. Pairing a daily protein range with a weekly look at your strength and weight trend is the approach Dyadfit is being built around.