High Protein Diet: How to Start One

A high protein diet has no official definition, but in practice it comes to about 100 g a day for a 70 kg adult. Trials use at least 1.5 g/kg, 20% of calories or 100 g, and the US Dietary Guidelines set a goal of 1.2–1.6 g/kg. For a 70 kg adult eating 2,000 kcal, all of those land between 84 and 112 g. I took the trial definitions from a 2018 meta-analysis and the goal from the Dietary Guidelines.

What counts as a high protein diet?

It depends on the study. The 2018 meta-analysis called a diet higher in protein if it gave 1.5 g/kg, 20% of energy or 100 g a day, or more. The table turns each definition into grams for a 70 kg (154 lb) adult eating 2,000 kcal.

Where the number comes from	What it says	At 70 kg and 2,000 kcal
Higher-protein trials in the 2018 meta-analysis	at least 1.5 g/kg a day	105 g
Same trials	at least 20% of energy	100 g
Same trials	at least 100 g a day	100 g
2025–2030 Dietary Guidelines goal	1.2–1.6 g/kg a day	84–112 g
Acceptable range for healthy adults	10% to 35% of calories	50–175 g

The definitions agree more than they look. Apart from the wide acceptable range, which is a floor and a ceiling, every row sits between 84 and 112 g. A practical high protein diet lands near 100 g here, or about 20% of a 2,000 kcal day.

Average intake starts below that. In US survey data from 2007 to 2010, adults ate 82.3 g a day and women 67.0 g, so for the average woman 100 g is a jump of 33 g. That gap is why the start needs a plan. For the reasoning behind the per-kilogram range, see how much protein you should eat a day.

How do I start a high protein diet?

Start with your own baseline, then add protein where you eat least. These are the four steps I’d use, in this order.

1. Log three ordinary days with grams, including snacks and drinks. Average the protein.
2. Set the target at your weight in kilograms times 1.2, rounded to a tidy number. Move toward 1.6 later if you want to.
3. Find your lowest-protein meal, usually breakfast, and add one protein food there.
4. Log three days again after two weeks and compare the average with the target.

I start at the low end because a small plan survives longer. Restarting after you drop an ambitious one costs more effort than adding a serving ever does. Spread the protein out too. The 2015 review by Leidy and colleagues suggested that 1.2–1.6 g/kg, possibly with at least 25–30 g of protein per meal, improves appetite and body weight management.

Step 3 is where the choice of food matters. This table ranks eight common additions by protein per 100 kcal, so you can see what each costs in calories.

Food (state)	Amount	Protein	Energy	Protein per 100 kcal
Light tuna, canned in water, drained	107 g	20.3 g	96 kcal	21.1 g
Chicken breast, braised	100 g	32.1 g	166 kcal	19.3 g
Greek yogurt, plain, nonfat	156 g	16.1 g	95 kcal	16.9 g
Cottage cheese, lowfat 2%	150 g	16.5 g	126 kcal	13.1 g
Tofu, firm, raw	126 g	21.8 g	181 kcal	12.0 g
Eggs, whole, large (2 eggs)	100.6 g	12.5 g	148 kcal	8.4 g
Lentils, boiled	198 g	17.9 g	230 kcal	7.8 g
Creamy peanut butter	32 g	7.7 g	189 kcal	4.1 g

Tuna, chicken and Greek yogurt buy the most protein per calorie, and peanut butter buys the least. Peanut butter is still fine to eat. It’s just an expensive way to buy protein in calories.

More isn’t better past a point. A meta-analysis of 49 trials found that protein supplements added no further fat-free mass once total intake passed 1.62 g/kg a day. Those trials used resistance training, so the finding is about lifters. It’s the reason I stop the plan at 1.6.

If deciding every day wears you out, cook ahead. Five boxes of high protein meal prep come to about 40 g each, high protein lunch meal prep covers the lunch side, and if you want the whole week mapped out, the high protein meal plan runs at 111 g a day.

Your height and weight go into the protein calculator, which returns a target inside the 1.2 to 1.6 g per kg range in the 2025–2030 Dietary Guidelines, with a floor of 60 g.

What does a day on a high protein diet look like?

Here is one for a 70 kg adult aiming at 1.5 g/kg, which is 105 g. Each row carries a link to the USDA record behind it.

Meal	Food and grams	Protein	Energy
Breakfast	Rolled oats, dry, 80 g	10.8 g	303 kcal
Breakfast	Greek yogurt, plain, nonfat, 156 g	16.1 g	95 kcal
Breakfast	Banana, 115 g	0.9 g	101 kcal
Lunch	Light tuna, canned in water, drained, 107 g	20.3 g	96 kcal
Lunch	Whole-wheat bread, 2 slices, 64.2 g	7.9 g	163 kcal
Lunch	Gala apple, 180 g	0.2 g	99 kcal
Snack	Raw almonds, 28 g	6.0 g	163 kcal
Dinner	Chicken breast, braised, 100 g	32.1 g	166 kcal
Dinner	White rice, dry weight, 90 g	6.3 g	333 kcal
Dinner	Broccoli, boiled, 156 g	3.7 g	55 kcal
Dinner	Olive oil, 13.5 g	0.0 g	119 kcal
Total		104.3 g	1,694 kcal

The day gives 104.3 g of protein, or 1.49 g/kg. Breakfast has 27.7 g and lunch 28.5 g, which clears the review’s 25–30 g per meal. At 1,694 kcal it’s a small day, and fruit, rice or oil would fill the rest while adding little protein.

Does a high protein diet help with weight loss?

A little, in the studies. The Leidy review reports that pooled results from short, tightly controlled feeding studies favored higher protein. People lost more weight and fat and kept more lean mass. Longer studies gave limited and conflicting results, and the gains showed up in people who stuck to the diet.

How big is the effect? A meta-analysis of 24 trials with 1,063 people puts a number on it. The trials lasted 12.1 weeks on average. In low-fat diets with equal calories, higher-protein versions gave 0.79 kg more weight loss and 0.87 kg more fat loss than standard-protein ones. That is a real effect, and it’s under a kilogram.

Protein doesn’t move the calorie floor. The AHA/ACC/TOS guideline describes typical weight-loss targets of 1,200 to 1,500 kcal a day for women and 1,500 to 1,800 for men. Never cut calories below the lower number of your range to fit in a protein goal.

Who should ask a doctor first?

People with kidney disease come first. The NIDDK page on kidney nutrition says some people with chronic kidney disease may need moderate protein. It sends them to a dietitian or health care professional for the balance. Older people with an estimated GFR below 30 who are not on dialysis may need to limit protein too, says the PROT-AGE study group. Pregnancy and breastfeeding change the figures, and this guide is written for adults 18 and over.

For everyone else, MedlinePlus puts the top of the range at 35% of your calorie needs, which is 175 g at 2,000 kcal.

If counting calories has started to feel hard to stop, or eating feels out of control, talk to someone: ANAD in the US (1-888-375-7767), Beat in England (0808 801 0677), NEDIC in Canada (1-866-633-4220) or the Butterfly Foundation in Australia (1800 33 4673). If you’re in danger right now, call your local emergency number. Other UK numbers and crisis lines are on our crisis support page.

I’d begin with one extra serving at the weakest meal and leave the rest of the plan for week two.