How much protein do I need a day?

Short answer: if you’re active, aim for about 1.6 to 2.2 g of protein per kg of body weight a day. For a 70 kg person, that’s roughly 110 to 155 g. If you mostly sit, less is fine. If you’re losing fat or building muscle, a bit more helps.

You’ll often see 0.8 g per kg quoted as “the” protein requirement. That number is the minimum to avoid a deficiency in someone who barely moves. Not falling short isn’t the same as eating what’s best for you.

How much protein, by goal

Your need depends on how much you move and what you’re trying to do. In grams per kg of body weight, per day:

These line up with the research. The International Society of Sports Nutrition (Jäger et al., 2017) puts most people who exercise at 1.4 to 2.0 g per kg. Studies on strength training (Morton et al., 2018) find muscle gains level off around 1.6 g per kg. And when trained people eat less to lose fat, needs go up (Helms et al., 2014), to around 2.3 to 3.1 g per kg of lean mass, to hold on to muscle.

Some people need more without training more: if you’re recovering from injury or surgery, ill, under a lot of physical stress, or older.

How much protein after 65

As you age, your body gets worse at using the protein you eat. Experts on protein in older people recommend at least 1.0 to 1.2 g per kg a day for healthy older adults, at least 1.2 g if you’re active, and 1.2 to 1.5 g with a long-term illness. The calculator lifts the low end to 1.2 when you tick “65 or older”.

The calculator also has its own page, if you want to bookmark it.

How much protein per meal

Your body can’t store protein the way it stores carbs and fat, so it works best spread over the day rather than in one big dinner. For most people, that means 20 to 40 g at each meal.

The easiest way to get there without weighing anything: use your hand.

• One palm of cooked meat, fish, tofu, tempeh or eggs is about 20 to 30 g of protein.
• Most people do well with 1 to 2 palms per meal.
• Bigger people have bigger hands, so it scales on its own.

If you’re very active and need more, add a palm or add a meal. More than two palms in one sitting can be a lot to digest.

Why protein matters when you’re losing weight

When you eat less than you burn, your body takes energy from fat, but also from muscle. Enough protein tips the balance toward fat.

It helps in two more ways:

• It keeps you full. Protein is the most filling of the three macros. Meals built around it hold you longer.
• It costs more to digest. Your body burns more energy breaking down protein than carbs or fat.

That’s why the top of the range is for people losing fat: you’re eating less, so each meal has to work harder.

Is too much protein bad for your kidneys?

Not if your kidneys are healthy. Reviews of the research (Devries et al., 2018) find no difference in kidney function between people eating more protein and people eating less. In one year-long study (Antonio et al., 2016), trained men spent months eating over 3 g per kg a day, with no harm to their kidneys or liver.

It’s also hard to overdo in practice. Protein is so filling that very high amounts are tough to eat.

The exception: if you have kidney disease, or a condition like PKU, you may need less protein, not more. Ask your doctor for your number.

Where to get your protein

There’s no single best protein. A mix is better than relying on one food.

• Animal: chicken, turkey, beef, pork, fish, seafood, eggs, Greek yogurt, cottage cheese.
• Plant: beans, lentils, chickpeas, tofu, tempeh, edamame.
• Powders: whey, casein, pea or rice protein. Handy to fill a gap, not a replacement for food.

Eating plant-based? You can hit your number too. Eat enough overall, mix your sources through the day, and aim for about a cup of beans or lentils daily. A plant protein powder helps if you’re still short.

Tracking it without the math

Knowing your number is step one. Hitting it every day is where most people lose track: how much protein was in that lunch, again?

That’s the part Fabee does for you. Tell it what you ate and it counts the protein in every meal, so you can see where you stand by dinner. If you’re still working out your calories too, start with how many calories you should eat a day.