Walk into any gym and ask five people how much protein they eat, and you’ll get five different answers. Some will say a gram per pound of bodyweight. Others will warn you that too much protein hurts your kidneys. Neither answer is fully right, and the confusion isn’t your fault. Protein advice online is a mess of outdated rules and gym myths.

Here’s what the actual research says, in plain terms, with the studies linked so you can check them yourself.

The basic number everyone starts from

The general recommendation for protein, the one printed on nutrition labels and used by most health agencies, is about 0.8 grams per kilogram of bodyweight per day. For a 70 kg (154 lb) person, that’s roughly 56 grams a day.

This number matters, but it’s often misunderstood. It’s not the amount you need to build muscle or perform well in the gym. It’s the amount that prevents deficiency in a mostly sedentary person. Think of it as a floor, not a target. If you train regularly, this number is too low for you.

What people who train actually need

The International Society of Sports Nutrition (ISSN) publishes the most widely cited research summary on this topic. Their position, based on a full review of the science, is that people who exercise regularly need 1.4 to 2.0 grams of protein per kilogram of bodyweight per day to build and maintain muscle. For that same 70 kg person, that works out to 98 to 140 grams a day, roughly double the general recommendation.

During a fat-loss phase, when you’re eating fewer calories, the number climbs higher. The ISSN notes that people doing resistance training on a calorie-restricted diet may need 2.3 to 3.1 grams per kilogram to hold onto muscle while losing fat. This makes sense. Protein helps protect muscle tissue when your body is short on overall calories.

A large 2018 review backs this up with harder numbers. Researchers led by Morton and colleagues pooled data from 49 studies and more than 1,800 participants and found that protein supplementation, combined with resistance training, reliably increases muscle mass and strength compared to training alone. The benefit leveled off at around 1.6 grams per kilogram per day. Eating more than that didn’t clearly help most people build more muscle.

The practical takeaway: most people who lift weights regularly should aim for somewhere between 1.6 and 2.0 grams per kilogram of bodyweight per day. That’s a wide enough range to fit almost any goal, from general strength training to serious muscle building.

Does protein timing actually matter?

You’ve probably heard about the “anabolic window,” the idea that you need to slam a protein shake within 30 minutes of finishing your workout or you’ll lose your gains. This idea is mostly outdated.

The ISSN’s own position on nutrient timing is clear: your total protein intake across the whole day matters far more than hitting a specific window after training. The muscle-building effect of a workout actually lasts at least 24 hours, not 30 minutes, and it gradually fades rather than slamming shut.

That said, timing isn’t completely irrelevant. A few things are worth knowing:

• Spread your protein out. The research suggests eating protein every 3 to 4 hours, in doses of about 20 to 40 grams each, works better than eating it all in one or two huge meals. This keeps your body’s muscle-building machinery consistently active through the day.
• Leucine matters. Each of those protein doses should ideally contain 700 to 3,000 milligrams of leucine, a specific amino acid that acts like a trigger switch for muscle building. Whey protein is naturally high in leucine, which is part of why it’s such a popular choice after training.
• Before bed counts too. Eating 30 to 40 grams of a slow-digesting protein like casein before sleep can boost muscle repair overnight without any downside, according to the same ISSN review.

So no, you don’t need to panic if you don’t drink a shake the second you rack your weights. You do need to hit your daily total and spread it out reasonably well.

The kidney myth, finally settled

This is one of the most persistent fears around eating more protein, and it’s worth addressing directly because it stops a lot of people from eating enough.

In 2018, researchers at McMaster University, led by kinesiology professor Stuart Phillips, reviewed more than two dozen studies comparing high-protein diets against normal or lower-protein diets in healthy adults. High-protein was defined generously: at least 1.5 grams per kilogram, at least 20% of calories from protein, or over 100 grams a day.

The result: no meaningful difference in kidney function between the groups. As Phillips put it, “there’s just no evidence to support this hypothesis. In fact, the evidence shows the contrary is true: higher protein increases, not decreases, kidney function.” The study, published in the Journal of Nutrition, found this held true even for people with risk factors like obesity or type 2 diabetes.

One important caveat: this research applies to people with healthy kidneys. If you already have diagnosed kidney disease, protein intake is something your doctor should manage directly, since the guidance is genuinely different for damaged kidneys than for healthy ones. If that applies to you, talk to your doctor or a registered dietitian before making changes to your protein intake.

Food first, but supplements have a real job to do

You can absolutely hit these protein targets through whole foods alone. Chicken, eggs, fish, dairy, beans, and lentils all get the job done. But the ISSN review makes a fair point: for people training hard and often, hitting 140+ grams of protein a day through food alone takes real planning, and a lot of cooking.

This is where protein powder earns its place, not as a magic supplement, but as a convenient, consistent way to close the gap between what you eat and what your training demands. A single scoop typically delivers 20 to 30 grams of high-quality, leucine-rich protein with minimal prep and minimal calories from fat or carbs attached.

If protein powder is already part of your routine, buying it in smaller tubs tends to cost more per serving and means more frequent reordering. For anyone training consistently, looking at bulk protein Canada options usually works out cheaper per scoop and means one less thing to think about mid-month. It’s a small logistics decision, but for people who go through protein daily, it adds up.

Putting it all together

Here’s the short version, if you skipped straight to the bottom:

• The general 0.8 g/kg recommendation is a minimum for inactive people, not a target for anyone who trains.
• Most people who lift weights regularly should aim for 1.6 to 2.0 grams of protein per kilogram of bodyweight per day.
• Spread that protein across 3 to 4 meals or snacks a day, aiming for 20 to 40 grams each.
• Total daily intake matters more than hitting a tight post-workout window.
• High protein intake doesn’t damage healthy kidneys, based on the best available research. If you have existing kidney disease, talk to your doctor first.
• Food should do most of the work, but protein powder is a legitimate, well-studied way to fill the gap, especially for people with high training volume.

This article is meant to give you a clear, evidence-based starting point, not a personalized nutrition plan. If you have a specific health condition, are pregnant, or are unsure what’s right for your body, check with a doctor or registered dietitian before making major changes to your diet.