Turning a Protein Target Into Daily Grams

Almost every protein recommendation you will read is expressed as grams per kilogram of body weight — “aim for 1.6 to 2.2 g/kg.” That is useless as a plan until you turn it into a single number you can eat to. This article does exactly that: it shows the one multiplication that converts a g/kg target into daily grams, gives you a range that fits muscle preservation in a deficit, and then confronts the real obstacle — that a GLP-1 makes the arithmetic trivial and the eating hard.

Once you have a target, the Lean-Mass Preservation Planner shows what that protein level does to the estimated fat-versus-lean split of your weight loss, and the Protein Intake Calculator will run the gram math for you if you would rather not do it by hand.

The one calculation

The whole conversion is: daily grams = target (g/kg) × your body weight in kilograms.

If you weigh in pounds, first divide by 2.2 to get kilograms. That is it. An example makes it concrete for someone weighing 180 lb (about 82 kg):

Target (g/kg)	Daily protein	What it represents
1.2 g/kg	~98 g	Adequate floor; could be higher in a deficit
1.6 g/kg	~131 g	Lower edge of the muscle-preservation range
2.0 g/kg	~164 g	Solidly protective during weight loss
2.2 g/kg	~180 g	Upper end for lean, hard-training dieters

So the same person has a target somewhere between roughly 130 and 180 grams a day depending on where in the range they aim. Notice the tidy coincidence at the top: 2.2 g/kg is almost exactly 1 gram per pound of body weight, which is why that “gram per pound” rule of thumb persists — it is a decent shorthand for the upper end of the range.

Which number in the range to pick

The evidence for muscle preservation in a deficit clusters around 1.6–2.2 g/kg, and the honest answer to “which number” is: the leaner you are and the larger your deficit, the higher you should aim. Two lines of research anchor this:

• Longland and colleagues put men in a steep (~40%) energy deficit with hard training. The group eating 2.4 g/kg gained about 1.2 kg of lean mass and lost more fat than the group at 1.2 g/kg, which merely held its muscle. Higher protein did not just protect lean mass — at that training load it built some while fat fell.
• Helms and colleagues, reviewing dieting resistance-trained athletes, concluded protein needs are roughly 2.3–3.1 g per kg of fat-free mass, scaling up “with the severity of caloric restriction and leanness.” Expressed against total body weight for most people, that lands in the same 1.8–2.7 g/kg neighborhood.

For most people on a GLP-1 — who are typically carrying more fat and not training like competitive athletes — targeting the 1.6–2.0 g/kg band is a sensible, evidence-aligned goal. Our deeper dives on protein to keep muscle in a deficit and how much protein on Wegovy or Zepbound walk through the targets in more detail.

One nuance worth flagging: if you carry a lot of excess weight, scaling protein off goal weight or fat-free mass rather than current weight avoids an inflated target. We cover that choice in protein by goal weight vs current weight.

Why the GLP-1 makes the number hard to hit

Here is the twist that makes this article necessary rather than just a multiplication lesson. GLP-1 medications work by slowing gastric emptying and blunting appetite, so total food volume drops — often sharply. That does not lower your protein target; muscle preservation still demands the same grams. It just makes those grams harder to physically consume, because you feel full faster and food is less appealing.

The result is a widening gap between the number on the calculator and the number on your plate. Protein also happens to be the most satiating macronutrient, so it fills you up quickly and can crowd itself out. The substudy data are the reason this matters: in SURMOUNT-1, roughly a quarter of the weight lost was lean tissue, and under-eating protein is one of the few things that can push that share higher. The medication drives the total loss; your protein intake helps decide how much of it is muscle.

Practical ways to actually hit the grams

Closing the gap is a logistics problem more than a nutrition one. What tends to work:

• Front-load protein. Appetite is often best earlier in the day; eat your largest protein serving when you can still stomach it rather than saving it for a dinner you may not finish.
• Make protein the anchor of every meal. Build the plate around the protein and add the rest around it, instead of the reverse.
• Use liquids strategically. A protein shake asks less of a suppressed appetite than a chicken breast. See do protein shakes work on a GLP-1 for where they help.
• Spread it out. Splitting protein across three or four feedings supports muscle better than one large dose — the logic is in protein per meal on a GLP-1.
• Track for a few days. Most people badly overestimate their intake; a short logging stint reveals the real gap.

For the full playbook on eating enough when nothing appeals, see hitting your protein target when you have no appetite, and for why the whole thing matters more on these drugs, why protein matters more on a GLP-1.

The takeaway

Turning a protein target into daily grams is one multiplication: g/kg times your weight in kilograms. For muscle preservation in a deficit, aim in the 1.6–2.2 g/kg band, higher if you are lean or dieting hard. The math is easy; the eating is not, because a GLP-1 suppresses the very appetite you need to hit the number — which is exactly why deliberate, front-loaded, protein-anchored meals matter. Run your figure through the Protein Intake Calculator, then see how that protein level shifts your estimated muscle-versus-fat loss in the Lean-Mass Preservation Planner. This is educational content, not medical advice — protein needs change with kidney health, age, and other conditions, so check with your clinician.

Sources

• Longland et al. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss (Am J Clin Nutr)
• Helms et al. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes (Int J Sport Nutr Exerc Metab, via PubMed)
• SURMOUNT-1 body composition (DXA) substudy (Diabetes, Obesity and Metabolism, via PMC)