How much protein should an adult eat per day?

The Health Canada RDA is 0.8 g per kilogram of body weight per day, which is the amount that prevents deficiency in nearly all sedentary adults. If you train, the Dietitians of Canada and ACSM joint position puts it at 1.2 to 2.0 g/kg, and the ISSN at 1.4 to 2.0 g/kg. A 2018 meta-analysis in the British Journal of Sports Medicine found no extra muscle gain above about 1.6 g/kg. For a 75 kg adult that's 60 g at the RDA and 90 to 150 g if you train.

How much protein can your body use in one meal?

More than the 20 to 30 g people quote. A 2018 review in the Journal of the ISSN concluded that about 0.4 g/kg per meal across at least four meals is the practical target for building muscle, with 0.55 g/kg per meal as the upper end. For a 75 kg person that's roughly 30 g per meal, four times a day. Extra protein in one sitting isn't wasted, it just isn't used for muscle as efficiently.

Is a high protein diet bad for your kidneys?

Not if your kidneys are healthy. A 2018 meta-analysis in the Journal of Nutrition pooled 28 trials with 1,358 adults without kidney disease and found higher protein intakes, 1.5 g/kg and up, did not change kidney function. People with existing kidney disease are a different case and should follow their doctor's limits.

Do you need protein right after a workout?

The total for the day matters far more than the clock. A 2013 meta-analysis in the Journal of the ISSN found that once total protein intake was accounted for, timing around the workout made no significant difference to strength or muscle size. Eating protein within a few hours either side of training is fine. Eating enough across the day is what counts.

How much protein should I eat to lose weight?

1.2 to 1.6 g/kg per day, with at least 25 to 30 g per meal, according to a 2015 review in the American Journal of Clinical Nutrition. Higher protein during a calorie deficit helps keep muscle and takes the edge off hunger. Lean, resistance-trained people cutting hard may need more, around 2.3 to 3.1 g per kilogram of fat-free mass.

Do older adults need more protein?

Yes. The PROT-AGE study group recommends 1.0 to 1.2 g/kg per day for healthy adults over 65, which is above the general 0.8 g/kg RDA, and 1.2 g/kg or more for older adults who exercise. Those with an acute or chronic illness may need 1.2 to 1.5 g/kg.

How many grams of carbs do you need a day?

Health Canada's RDA is 130 g per day, which is the amount the brain uses. The acceptable range is 45 to 65% of your calories. If you train, the Dietitians of Canada and ACSM joint position scales carbohydrate to training load, from about 3 g/kg per day for light activity up to 10 g/kg for very heavy endurance training.

How much fibre should you eat a day?

Health Canada's adequate intake is 38 g a day for men and 25 g for women aged 19 to 50, dropping to 30 g and 21 g after 50. Most Canadians eat about half that.

How much sodium is too much?

Health Canada sets the adequate intake at 1,500 mg a day for adults, and 2,300 mg as the level above which cutting back reduces chronic disease risk. The WHO's limit is 2,000 mg of sodium, which is 5 g of salt. One teaspoon of table salt is about 2,300 mg of sodium.

How much protein, carbs, fat and fibre adults need

These are the reference numbers for the main nutrients, in the units the research uses. Most are per kilogram of body weight, so weigh yourself in kilos and multiply. The short version is in the table. The sections after it say where each number comes from and when it applies to you.

A 75 kg adult is used for the worked examples. Swap in your own weight.

The numbers

Nutrient	Amount	Who says so
Protein, minimum	0.8 g/kg/day	Health Canada DRI
Protein, if you train	1.2 to 2.0 g/kg/day	Dietitians of Canada / ACSM; ISSN says 1.4 to 2.0
Protein, over 65	1.0 to 1.2 g/kg/day	PROT-AGE
Protein, losing weight	1.2 to 1.6 g/kg/day	Leidy 2015, AJCN
Carbohydrate, minimum	130 g/day	Health Canada DRI
Carbohydrate, range	45 to 65% of calories	Health Canada DRI
Carbohydrate, if you train	3 to 10 g/kg/day by load	Dietitians of Canada / ACSM
Fat	20 to 35% of calories	Health Canada DRI
Saturated fat	under 10% of calories	WHO 2023
Trans fat	under 1% of calories	WHO
Fibre	38 g men, 25 g women (19 to 50)	Health Canada DRI
Sodium	1,500 mg adequate, 2,300 mg upper	Health Canada DRI
Free sugars	under 10% of calories, 5% is better	WHO 2015

Protein

0.8 g/kg is the floor, not the target. That’s the Recommended Dietary Allowance in Health Canada’s DRI tables. It’s set to cover the needs of 97.5% of healthy sedentary adults, which means it’s the amount that stops you being deficient. The average requirement is lower still at 0.66 g/kg. Neither number was designed for someone lifting weights or trying to keep muscle while dieting. For a 75 kg adult it works out to 60 g a day.

1.2 to 2.0 g/kg if you train. The joint position of the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine (2016) puts protein for active people in that range. The ISSN position stand (2017) lands at 1.4 to 2.0 g/kg for building or keeping muscle. At 75 kg that’s 90 to 150 g a day.

Above about 1.6 g/kg, more protein stops adding muscle. Morton and colleagues (2018) pooled 49 trials with 1,863 people and found that protein beyond 1.62 g/kg per day gave no further gain in fat-free mass from resistance training. That’s 120 g for a 75 kg adult, and it’s a good default if you train and aren’t dieting hard.

1.0 to 1.2 g/kg after 65. Older adults get less muscle-building response from the same protein, so the PROT-AGE group (2013) recommends at least 1.0 to 1.2 g/kg, and 1.2 g/kg or more for those who exercise. People over 65 with an illness may need 1.2 to 1.5 g/kg.

More when losing weight. In a calorie deficit, protein is what keeps the weight you lose from being muscle. Leidy and colleagues (2015) put the useful range at 1.2 to 1.6 g/kg with 25 to 30 g per meal. For already lean, resistance-trained people on a hard cut, Helms and colleagues (2014) estimated 2.3 to 3.1 g per kilogram of fat-free mass, scaled up with how lean you are and how big the deficit is. That last one is for the end of a contest prep, not a normal diet.

The PocketChomp macro calculator uses 1.2 to 1.6 g/kg as its default range and 1.6 to 2.0 g/kg for the high-protein split, for the reasons above.

Carbohydrate

130 g a day is the RDA, and it’s the amount of glucose the brain gets through. It isn’t a target for most people, it’s the minimum before the body has to make glucose from other things.

45 to 65% of calories is the acceptable range in the DRI tables. On 2,000 calories that’s 225 to 325 g a day.

If you train, it scales with load. The 2016 joint position gives carbohydrate in g/kg per day by how much you do, from about 3 g/kg for light training up to 10 g/kg for several hours a day of endurance work. A 75 kg recreational lifter is at the low end, around 225 to 375 g. A marathoner in a heavy week is at the top.

There’s no evidence that carbs themselves cause fat gain at a given calorie intake. The 2015 AJCN review above and the position papers treat total calories and protein as the levers, with carbohydrate filling in around training needs.

Fat

20 to 35% of calories is the DRI range. The WHO fact sheet on healthy diet says 30% or less. On 2,000 calories, 20 to 35% is 44 to 78 g a day.

Saturated fat under 10% of calories, trans fat under 1%. Both are in the WHO 2023 guideline on saturated and trans fat. On 2,000 calories that’s under 22 g of saturated fat.

Two fats you need to get. The DRI tables set an adequate intake for alpha-linolenic acid (the plant omega-3) at 1.6 g a day for men and 1.1 g for women, and for linoleic acid (omega-6) at 17 g for men and 12 g for women, dropping to 14 g and 11 g after 50. Most people get the omega-6 without trying. The omega-3 takes a bit of fish, flax, walnuts or canola.

Fibre

Health Canada’s adequate intake is 38 g a day for men and 25 g for women aged 19 to 50, and 30 g and 21 g after 50. Health Canada says most Canadians get about half that, which is why fibre is a useful thing to track on its own. The DRI table above has the figures by age.

Sodium and sugar

Not macros, but the two numbers people ask about most.

Sodium: 1,500 mg adequate, 2,300 mg upper. Health Canada’s DRI table for elements gives 1,500 mg a day as the adequate intake for adults, and 2,300 mg as the Chronic Disease Risk Reduction level, which is the point above which eating less is expected to reduce risk. The WHO’s limit is 2,000 mg of sodium, or 5 g of salt. A teaspoon of table salt is about 2,300 mg of sodium. Health Canada’s 2017 estimate put the average Canadian at 2,760 mg a day, with 77% of it coming from processed and restaurant food rather than the shaker.

Free sugars: under 10% of calories. The WHO 2015 sugars guideline sets 10% as the strong recommendation, which is about 50 g on 2,000 calories, and says 5% or less may bring extra benefit. Free sugars are the ones added to food plus the sugar in juice, honey and syrups. Sugar inside whole fruit and milk doesn’t count.

Sources

Health Canada, Dietary Reference Intakes: reference values for macronutrients.
Health Canada, Dietary Reference Intakes: reference values for elements.
Thomas, Erdman and Burke. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. Med Sci Sports Exerc, 2016.
Jäger et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr, 2017.
Morton 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.
Bauer et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc, 2013.
Leidy et al. The role of protein in weight loss and maintenance. Am J Clin Nutr, 2015.
Helms et al. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes. Int J Sport Nutr Exerc Metab, 2014.
Schoenfeld and Aragon. How much protein can the body use in a single meal for muscle-building? J Int Soc Sports Nutr, 2018.
Schoenfeld, Aragon and Krieger. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr, 2013.
Devries et al. Changes in kidney function do not differ between healthy adults consuming higher- compared with lower- or normal-protein diets. J Nutr, 2018.
Health Canada, Sodium intake of Canadians in 2017 and Fibre.
WHO, Healthy diet fact sheet, updated January 2026.
WHO, Saturated fatty acid and trans-fatty acid intake for adults and children, 2023.
WHO, Guideline: sugars intake for adults and children, 2015.

This is general nutrition information from public guidelines, not medical advice. If you have kidney disease, diabetes or another condition that changes what you should eat, follow your clinician’s numbers over these.