How much protein should you eat to lose weight?

How much protein do you actually need?

There's no single number — your protein needs depend on your size, your goal, and how active you are. The official RDA for adults is just 0.8 grams per kilogram of body weight¹ a day, but that's the minimum to avoid deficiency, not the amount that's best for losing weight or building muscle. For most people working on their body composition, research points much higher — roughly 1.2 to 2.0+ grams per kilogram a day. The calculator above turns that into a personalized daily target and a per-meal range.

Why protein matters when you're losing weight

Protein pulls more weight than any other macronutrient when you're trying to lose fat:

• It keeps you full. Protein is the most satiating macronutrient, which makes a calorie deficit far easier to sustain without constant hunger.
• It protects lean muscle. In a calorie deficit your body can burn muscle for fuel — eating enough protein steers more of the loss toward fat and preserves the muscle that keeps your metabolism strong.
• It costs more to digest. Protein has the highest thermic effect of any macro: your body burns about 20–30% of protein's calories just processing it, versus 5–10% for carbs and 0–3% for fat.³
• It's critical on a GLP-1. Medications like semaglutide and tirzepatide curb appetite, making it easy to under-eat protein at exactly the moment muscle loss is a risk.

How much protein to lose weight

Research consistently shows that eating well above the RDA — about 1.2 to 1.6 grams per kilogram of body weight per day², and up to roughly 2.0 g/kg if you're very active or in a steep deficit — preserves lean muscle while you lose fat. For a 150-pound (68 kg) person, that's roughly 80 to 120 grams a day, compared with only about 55 grams at the basic RDA. Eating toward the higher end is one of the best ways to protect muscle, especially on a GLP-1.

Daily protein target by body weight

As a quick reference, here's the 1.2–1.6 g/kg weight-loss range applied to common body weights. Because protein needs track lean mass, people carrying more body fat should lean toward the lower end — the calculator above does this for you by estimating lean body mass.

How much protein to build muscle

To build muscle, aim higher still — about 1.6 to 2.2 grams per kilogram per day⁵, paired with regular resistance training. Going much beyond that doesn't add benefit. Just as important as the daily total is how you spread it: research shows 20 to 40 grams of high-quality protein per meal⁴ maximizes muscle protein synthesis (the repair-and-grow process), which beats loading it all into a single meal.

How this calculator estimates your target

Most calculators just multiply your total body weight by a fixed number. We go a step further: we estimate your lean body mass from your height, weight, and sex (the Boer formula), then set your protein per kilogram of lean mass, scaled to your goal and activity. Because it's muscle — not fat — that drives protein needs, this gives a more tailored number, and it's why your height and sex change the result here. Your per-meal figure splits the daily total across three meals.

High-protein foods to build meals around

When weight loss is the goal, lean, lower-fat sources give you the most protein for the fewest calories. Approximate protein per 100 g (about 3.5 oz) cooked:

Can you eat too much protein?

For most healthy adults, no. Intakes up to about 2 g/kg (studies suggest up to ~2.2 g/kg) are safe, with no evidence of harm to the kidneys, liver, or bones. Problems become more likely only above roughly 3–4 g/kg, or in people who already have kidney disease. If you have kidney disease or another condition that affects how you process protein, talk with a clinician before making big changes.

Pair it with your other numbers

Protein is one piece of the puzzle. See how many calories to eat with our calorie deficit calculator and TDEE calculator, check where your weight falls with the BMI calculator, and dial in hydration with the water intake calculator.

This Protein Calculator provides a general estimate of daily protein intake based on height, weight, sex, activity level, and goals. It may not reflect the needs of people with very high muscle mass, kidney disease, pregnant or breastfeeding women, children, older adults, or those with specific health conditions, and it should not be used as a sole diagnostic tool. It does not determine eligibility for any medication or treatment. Talk with a JumpstartMD clinician for guidance tailored to you.

References

1. Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press; 2005. ↩
2. Leidy HJ, Clifton PM, Astrup A, et al. The role of protein in weight loss and maintenance. Am J Clin Nutr. 2015;101(6):1320S–1329S. ↩
3. Pesta DH, Samuel VT. A high-protein diet for reducing body fat: mechanisms and possible caveats. Nutr Metab (Lond). 2014;11:53. ↩
4. Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. ↩
5. Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training–induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376–384. ↩