Protein vs carbs: What active people actually need

Trying to decide between going big on protein or fuelling up on carbs before your gym session? We asked sports nutrition experts what your body really needs to help you train better.

About half our daily calorie intake should come from carbohydrates, external. These are found in starchy foods such as bread, pasta, rice, couscous, potatoes, breakfast cereals, oats and other grains like rye and barley.

As for protein, the average adult needs about 0.75g protein per kilogram of body weight per day.

In short, yes.

Proteins contain amino acids, which are the building blocks for muscle growth. So athletes should up their protein requirements to about 1.2–2.0g of protein per kilogram of body weight per day, says the British Nutrition Foundation.

Someone training three to five hours per week is recommended to have 3–5g of carbohydrates per kilogram of body weight per day, external, while those training at least two hours a day needs up to 8g, external.

Their physiological make-up means they can handle the increased carb intake, says Dr Michael Newell, sport and exercise nutrition lecturer at University of Westminster.

"Endurance athletes have been selected for the sport because they're very good at it and also because they are exceptionally good at consuming high rates of carbohydrates – those two things need to go together. You don't get an elite marathon runner who can't consume carbohydrates at a high rate."

Professional athletes get expert nutritional advice based on their weight, sport and physiology.

Tom Huelin, fitness coach at vegan football club Forest Green Rovers, external, says the amount of protein and carbs he prescribes also depends on the players' schedule.

"On the days they're going to be working harder they consume more carbs, and they make sure after intensive sessions they receive a top-up of protein to help with muscular fatigue."

The average gym-goer, however, doesn't usually have access to that kind of guidance.

Diet advice aimed at supporting exercise tends to fall into two camps: high-protein products to build strength or reducing carb intake to improve performance.

But sport dietitians Alexandra Cook prefers a more balanced approach. This means no extremes of either protein or carbs – and tailoring your diet to your own requirements rather than comparing it to someone else's.

"Some athletes – especially in the ultra-endurance world – do tend to go for this low-carb approach and it works for them. That doesn't mean it's going to work for everybody else," she says.

"I know for sure if I cut out carbohydrates, I probably wouldn't be able to get out of bed, let alone run a 50-mile race."

Newell says if you want to train consistently, it would be "ridiculous" to exclude any macro-nutrient.

"You need carbohydrates to sustain longer, high-intensity training, and you need protein to help recover from that and to replace amino acids you've lost. On top of that, you need a bit of fat to ensure you get an adequate number of calories in your diet."

Protein is vital for helping us perform and helps us repair and recover, says Cook. The good news is most active people get enough of it by eating a balanced, varied diet.

"If you have a portion of protein at each meal, and if you're doing slightly higher training loads you get protein from snacks like nuts, peanut butter and milk, you'll easily meet your protein requirements," she says.

Other sources include egg, fish and lean meat, according to the Eatwell Guide., external And if you eat too much protein? Don't worry - the body will just naturally get rid of it.

Plant proteins contain the same nine essential amino acids, external as animal-based protein sources, except one or two typically present at lower levels.

Dietitian Laura Tilt recommends loading up on lentils, peanut butter, hemp seeds, edamame and tinned chickpeas.

"If you eat a variety of plant proteins throughout the day and eat enough calories, your body will get sufficient essential amino acids," she adds.

Other sources include seitan, which is made from wheat, and nutritional yeast, while Huelin recommends soy milk to his players for its high-protein content.

Kind of. While there's research to support the view low-carb diets, external could help athletes, there's also plenty pointing to the opposite – that low-carb diets will inhibit exercise performance, external.

Does that mean carbs win the race?

They'll definitely give you the fuel you need to compete but you also need protein with comprehensive amino acids to repair and help build lean muscle mass.

The experts we spoke to all advocate that it's preferable not to cut any macro-nutrients out of your diet and to follow healthy eating guidelines - adapting them depending on your individual demands rather than going to extremes.

So, combined protein, carbohydrate and even fat should all help you cross that finish line – but unless you're an elite athlete, you'll almost certainly get enough of these from a healthy diet.

Originally published January 2020. Updated March 2026.

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