If your calories are already in check, protein is the next thing I would look at. It helps you hold on to muscle while you diet, and it keeps you full, so the deficit is easier to stick to. In my experience many people eat less of it than they need.
Short answer: For most active people, 1.6-2.2 g of protein per kilogram of body weight a day works well. At 80 kg that is roughly 130-175 g a day. If you are losing fat, I usually go toward the upper end. In a deficit, more protein helps you hold on to muscle and can make hunger easier to manage.
Why protein matters
- It keeps your muscle. In a deficit it helps you keep more of your muscle, so more of what you lose is fat.
- It fills you up. After a protein meal you go longer without hunger.
- It has a high thermic effect. Your body burns more energy digesting protein than it does for fats and carbs.
- It is building material. If you eat too little, your training will not give you the muscle it could.
How much to eat
For most active people, 1.6-2.2 g per kg of body weight a day works well. At 80 kg: 80 x 1.6 = 128 g, and 80 x 2.2 = 176 g. So you are talking about roughly 130-175 g a day. If you are losing fat, go for the upper end. For many people it also makes hunger easier to manage.
Where does this come from? A 2018 meta-analysis of resistance training studies (Morton et al.) found that in people doing resistance training, gains in fat-free mass stopped increasing above roughly 1.6 g per kg a day of total protein. The range of 1.6-2.2 g is what I use in practice, with some margin on top. A 2012 meta-analysis of 24 diet trials (Wycherley et al.) compared diets with the same calories. The higher-protein versions gave a small extra fat loss (under 1 kg over about 12 weeks) and less loss of lean mass.
Not sure what you eat now? The calculator gives you a calorie and protein target to start with. If you have kidney disease or any other medical condition, talk to your doctor before you change how much protein you eat.
Where to get it
- Meat and fish (chicken, turkey, beef, salmon, tuna)
- Eggs and dairy: quark (a fresh cheese, similar to strained Greek yogurt), Greek yogurt, skyr, cheese
- Beans, lentils and tofu (plant sources)
- Protein powder: a handy way to top up when normal food is not enough
To compare foods, use the protein tool. It ranks common foods by how much protein you get per 100 kcal (calories). You can also type in the price and pack size from your own shop and see what 100 g of protein costs you.
A practical tip
Try to put a protein source in every meal. It is the easiest way to reach your number without weighing every gram. Breakfast, lunch, dinner. Something with protein on the plate every time.
In a deficit, protein matters even more. See build muscle in a calorie deficit, and how to lose weight without exercise if training is not an option for you right now.
Frequently asked questions
Why is protein so important when you lose fat?
In a deficit it helps you keep more muscle, so more of the weight you lose is fat. Protein meals also tend to keep you full longer, and your body burns more energy digesting protein than fats and carbs.
Where do I get protein from?
From meat and fish, eggs and dairy (quark, Greek yogurt, skyr, cheese), beans, lentils and tofu. Protein powder is a handy way to top up when normal food is not enough.
How do I reach my number without counting every gram?
Put a protein source in every meal: breakfast, lunch and dinner. It is the easiest way to get to your number.
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Apply for coaching Get the free Fat Loss KitSources, so you can check:
1) Morton RW, 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. DOI: 10.1136/bjsports-2017-097608 | PMID: 28698222
2) Wycherley TP, et al. Effects of energy-restricted high-protein, low-fat compared with standard-protein, low-fat diets: a meta-analysis of randomized controlled trials. Am J Clin Nutr. 2012;96(6):1281-1298. DOI: 10.3945/ajcn.112.044321 | PMID: 23097268
Martin Barna
Online nutrition and fitness coach. Since 2013 I have worked with 600+ clients on fat loss. I work from research and from what I see with my clients.
Apply for coachingThis article is for information only. It is not medical advice. If you have a health condition, talk to your doctor.