Per meal and timing

Can I get enough protein eating in an 8-hour window?

By GyroscopeUpdated November 14, 20265 sources

Yes. Fit your daily range into two or three bigger meals, each well over your meal line. Protein past 30 g isn’t wasted. In a 2023 trial, 100 g of protein at once kept muscle building going for more than 12 hours, longer than 25 g did. The hard part is fitting enough food into eight hours.

The worry comes from a number that went around gyms for years: your body can only use about 30 g of protein at a time. If that were true, an 8-hour window with two meals would cap you at about 60 g, well under most people’s range. It’s a fair worry, and the evidence against it is newer than the rule.

We’d plan an 8-hour window around two or three meals that each carry a big share of the day, starting the window with protein instead of a pastry. Time-restricted eating can work fine for protein. It goes wrong when the first meal of the window is a bagel and the last is pasta.

A big protein meal works more like a slow cooker than a microwave. It keeps working for hours after you’ve put it on.

The trial that broke the 30 g rule

In 2023, Jorn Trommelen and colleagues gave 36 young men a whole-body workout and then a drink with 0, 25 or 100 g of milk protein, 12 men to each. They tracked the protein through the body with labeled amino acids for 12 hours. The 100 g drink gave a bigger response, and it was still going at 12 hours. Muscle building was about 20% higher than with 25 g in the first four hours and about 40% higher from hours four to twelve.

It was one session, in young men, and it measured building, not muscle growth over months. But it shows the body doesn’t throw away protein past 30 g. It uses it more slowly and for longer. See the myth that your body can only use 30 g at a meal.

The other side

An older study points the other way. In 2013, 80 g of whey over 12 hours as two 40 g doses built less muscle protein than four 20 g doses (four 20 g doses built 48% more). That was a leg workout and smaller doses, which may be why it differs. In a 2022 trial in adults aged 65 to 80, a day with 60% of the protein at dinner built muscle at the same rate as an evenly spread day.

Across 23 studies, a 2013 review found that once total protein was counted, the timing around workouts made no difference, and the total was the strongest predictor of growth. We’d do the same. Get the total in, and keep each meal well over your line.

An 8-hour day at 180 lb

The typical range at 180 lb is 100 to 130 g, with a 35 g meal line.

Grams from USDA FoodData Central. The first meal does most of the work, which is the opposite of how most people eat.

If your window ends early and you train late, put the biggest meal after the workout. If you’re on two meals, each needs to be about half your range, about 50 to 65 g at 180 lb.

Build your meals in the meal line calculator, and see where your day lands in Is my number enough? bodyfat.guide covers whether the window itself burns more fat.