Is 100 grams of protein a day too much?

For most adults, no. 100 grams is about 1.5 g/kg for a 150-pound person, which sits inside the 1.2 to 1.6 g/kg range supported by trials in older adults and people who train. It also falls within the 10 to 35 percent of calories range set by the National Academies. People with chronic kidney disease should check with their clinician before eating this much.

Can your body only absorb 30 grams of protein per meal?

Your body absorbs almost all of it. What plateaus is the muscle-building response. In one study, 30 grams of protein from lean beef raised muscle protein synthesis by about 50 percent, and 90 grams did not raise it further. The extra protein still gets used for other purposes, but spreading intake across meals gets more muscle benefit from the same total.

Should you use your current weight or goal weight to calculate protein?

If you are near a healthy weight, use current weight. If you carry a lot of excess body fat, use a goal weight or an estimate of lean mass. Fat tissue needs very little protein, so calculating from a high body weight can overshoot.

Do you need protein powder to hit these targets?

No. Three meals with a palm-sized serving of meat, fish, eggs, dairy, tofu, or legumes will get most adults to 1.2 g/kg. Powder is a convenience, not a requirement. The International Society of Sports Nutrition notes that whole foods can meet daily needs for active people.

Does eating more protein help you lose weight?

It helps you keep muscle while you lose fat. In a trial of athletes on a 40 percent calorie cut, the group eating about 2.3 g/kg lost 0.3 kg of lean mass versus 1.6 kg in the group at 1.0 g/kg. Fat loss was the same. Protein also tends to be more filling per calorie than carbohydrate or fat.

How Much Protein Do You Need Per Day?

The short answer: the official U.S. Recommended Dietary Allowance (RDA) is 0.8 grams of protein per kilogram of body weight per day. That works out to about 54 grams for a 150-pound adult. Most protein researchers now argue this is a floor, not a target. Adults over 65, people who lift weights, and people losing weight do better in the range of 1.2 to 1.6 grams per kilogram, which is 82 to 109 grams for the same 150-pound person.

What is the official protein RDA?

The Dietary Reference Intakes from the National Academies set the adult protein RDA at 0.8 grams per kilogram of body weight per day (NASEM DRI summary table). The number rises to 71 grams per day during pregnancy and lactation. The same report sets an Acceptable Macronutrient Distribution Range for protein of 10 to 35 percent of daily calories (NASEM AMDR table).

The RDA was set to prevent deficiency, not to optimize muscle, strength, or recovery. It also came from nitrogen balance studies, an older method that many researchers believe underestimates true needs. On a 2,000-calorie diet, the 10 to 35 percent range spans 50 to 175 grams. The RDA sits near the bottom.

Is 0.8 g/kg enough for older adults?

Most geriatric nutrition experts say no. In 2013, the PROT-AGE Study Group, convened by the European Union Geriatric Medicine Society, published a position paper on protein for adults over 65. It recommends at least 1.0 to 1.2 grams per kilogram per day for healthy older adults. It advises 1.2 or more for older adults who exercise, and 1.2 to 1.5 for those with acute or chronic illness (Bauer et al., JAMDA 2013).

The reason is biology. Aging muscle responds less to a given dose of protein, a change researchers call anabolic resistance. The gut and liver also extract more amino acids before they reach muscle. The same 0.8 grams per kilogram delivers less to muscle at 70 than at 30.

Newer measurement methods support the higher number. A 2015 study used the indicator amino acid oxidation technique in women over 65. It estimated the average requirement at 0.96 grams per kilogram and the population-safe intake at 1.29 grams per kilogram, well above the RDA of 0.8 (Rafii et al., J Nutr 2015). A 2018 review from McMaster University proposed that older adults consume at least 1.2 grams per kilogram per day (Traylor et al., Adv Nutr 2018).

Hormone changes drive part of age-related muscle loss too. Our guide to hormones and aging covers that side.

How much protein do you need if you exercise or lose weight?

More than the RDA. A 2018 meta-analysis in the British Journal of Sports Medicine pooled 49 randomized trials with 1,863 participants. Protein supplementation during resistance training increased fat-free mass by 0.30 kilograms and one-repetition-maximum strength by 2.49 kilograms on average. The benefit plateaued at a total intake of 1.62 grams per kilogram per day. Above roughly 1.6 grams per kilogram, extra protein added no further muscle (Morton et al., BJSM 2018).

The International Society of Sports Nutrition position stand recommends 1.4 to 2.0 grams per kilogram per day for most exercising people. It notes that this range still falls inside the 10 to 35 percent AMDR (Jager et al., JISSN 2017).

Weight loss raises the need again, because a calorie deficit can burn muscle for fuel. In a two-week trial of 20 resistance-trained athletes eating 60 percent of their usual calories, the group at about 1.0 grams per kilogram lost 1.6 kilograms of lean mass. The group at about 2.3 grams per kilogram lost only 0.3 kilograms. Fat loss was the same in both groups (Mettler et al., MSSE 2010). A separate systematic review of lean, resistance-trained athletes in a calorie deficit concluded that 2.3 to 3.1 grams per kilogram of fat-free mass is likely needed (Helms et al., IJSNEM 2014).

This matters most for people on GLP-1 medications, where rapid weight loss can strip muscle along with fat. Our sister site covers that in detail at glp1.md.

Is a high-protein diet bad for your kidneys?

Not in healthy people, based on the best available trial evidence. A 2018 systematic review and meta-analysis in the Journal of Nutrition examined 28 randomized controlled trials with 1,358 participants. It compared higher-protein diets (1.5 grams per kilogram or more, or at least 100 grams per day) with normal or lower-protein diets. The change in glomerular filtration rate did not differ between groups. The authors concluded that higher protein intakes do not adversely affect kidney function in healthy adults (Devries et al., J Nutr 2018).

The caveat is existing kidney disease. The National Institute of Diabetes and Digestive and Kidney Diseases notes that some people with chronic kidney disease may need to eat moderate amounts of protein so waste does not build up in the blood (NIDDK). The PROT-AGE paper makes the same exception for older adults with an estimated GFR below 30 who are not on dialysis. If you have kidney disease, diabetes, or high blood pressure, ask your clinician to check your eGFR first.

How should you spread protein across the day?

Evenly. Most people eat little protein at breakfast and a lot at dinner. Muscle does not bank protein for later, and it has a per-meal ceiling.

In a 2009 study, a 113-gram serving of lean beef with 30 grams of protein raised muscle protein synthesis by about 50 percent in both young and older adults. A 340-gram serving with 90 grams of protein did not raise it any further (Symons et al., JADA 2009). In a 2014 crossover trial, eating about 30 grams of protein at each of three meals produced 25 percent higher 24-hour muscle protein synthesis than a skewed pattern of 11, 16, and 63 grams. (Mamerow et al., J Nutr 2014).

The ISSN position stand gives a practical rule: about 0.25 grams per kilogram per meal, or 20 to 40 grams, spaced every 3 to 4 hours.

How many grams of protein for your body weight?

Divide your weight in pounds by 2.2 to get kilograms, then multiply by your target.

At the RDA of 0.8 g/kg (the minimum):

120 lb (54 kg): 44 g per day
150 lb (68 kg): 54 g per day
180 lb (82 kg): 65 g per day
200 lb (91 kg): 73 g per day
250 lb (113 kg): 91 g per day

At 1.2 g/kg (older adults, light activity):

120 lb: 65 g per day
150 lb: 82 g per day
180 lb: 98 g per day
200 lb: 109 g per day
250 lb: 136 g per day

At 1.6 g/kg (resistance training, weight loss):

120 lb: 87 g per day
150 lb: 109 g per day
180 lb: 131 g per day
200 lb: 145 g per day
250 lb: 181 g per day

If you carry a lot of body fat, use a goal weight instead. Fat tissue needs little protein. To make the grams concrete: a 4-ounce cooked chicken breast, a cup of Greek yogurt, or a cup of cooked lentils each supply roughly 20 to 35 grams. Three meals built around one of those lands most adults near 1.2 grams per kilogram. Our longevity nutrition guide covers what to put around the protein, and our primer on metabolic health basics explains why muscle mass matters for blood sugar.

The bottom line

The RDA of 0.8 grams per kilogram is a floor that prevents deficiency. For most adults, and especially for anyone over 65, lifting weights, or losing weight, 1.2 to 1.6 grams per kilogram is the range best supported by trials. For a 150-pound person that is 82 to 109 grams a day. Spread it across three or more meals of at least 20 to 30 grams each. Healthy kidneys handle this without harm. If you have kidney disease, get your eGFR checked and work with a dietitian first.

Last updated: August 2026. This article is for informational purposes only and does not constitute medical advice. Talk with your healthcare provider or a registered dietitian before making large changes to your protein intake, especially if you have kidney disease, diabetes, or liver disease.