A top nutrition scientist said people should focus more on fiber than protein. He shared how a mostly plant-based diet can help you get both macronutrients.

Tim Spector is a nutrition expert who thinks people should prioritize adding fiber to their diets instead of protein.

High-protein versions of foods such as cereal bars and pasta have taken over grocery-store shelves as people try to eat more of the macronutrient. But a top nutrition scientist said fiber should be our focus.

According to the US Department of Agriculture’s Dietary Guidelines for Americans for 2020 to 2025, more than half of Americans meet or exceed the minimum daily requirement for protein, which is 0.36 grams per pound of body weight.

Yet the guidelines say that more than 90% of women and 97% of men in the US don’t meet the recommended intake for dietary fiber.

Tim Spector, a British epidemiologist who cofounded the nutrition company Zoe, told B-17 that people who want to improve their diet should focus more on consuming fiber than on consuming protein. Fiber is great for gut health, can improve heart health, and can help ease constipation, among other things.

Rosa Becerra-Soberon, a registered dietitian at Top Nutrition Coaching, told B-17 that people should aim to have a well-balanced diet containing enough fiber and protein. Those who are particularly active and want to build or maintain lean muscle may need more protein than the amount the US government recommends, as fitness experts previously told B-17.

Spector shared three tips on how to hit your protein goals while getting enough fiber.

Prioritize plant-based protein sources, especially legumes

Spector recommends swapping meat for plant-based protein sources, such as beans, legumes, and nuts. 

Spector doesn’t eat meat often but wrote in his cookbook, which is set to be released in the US in 2025, that he still consumes about 1 gram of protein per kilogram of his body weight per day, mostly from plants and whole foods.

While plant-based protein sources tend to contain less protein overall than meat, they contain more fiber. According to the US Department of Agriculture, 100 grams of fried tofu contains about 18 grams of protein and 4 grams of fiber.

Becerra-Soberon said that if you don’t consume meat, you should make sure you get all the essential amino acids by eating grains and seeds.

Spector wrote that replacing meat with legumes is a great way to increase your fiber intake while meeting your protein needs. Legumes such as beans and lentils are protein-heavy but higher in fiber and typically better for the environment than meat.

For example, canned chickpeas contain about 8 grams of protein per 100 grams, as well as 7 grams of dietary fiber. Chicken has 22 grams of protein per 100 grams but no fiber, according to USDA data — and it tends to be more expensive than chickpeas.

The longevity researcher Dan Buettner previously shared dietitian-approved legume recipes with B-17.

Variety is key

Because plants generally contain less protein than meat, Spector wrote that he incorporates “a good mix” of plant-based protein sources into his diet throughout the day. This is because different whole foods contain different amounts of protein, so you might have to eat a “variety of nutrient-dense whole foods to take care of your protein needs,” he wrote.

Spector eats yogurt with fruit, nuts, and seeds for breakfast. 

For example, Spector’s go-to breakfast of yogurt, kefir, berries, nuts, and seeds contains about 30 grams of protein from multiple sources. He may also have butter beans with quinoa for lunch and a portion of tofu for dinner, he said.

Dr. Will Bulsiewicz, Spector’s colleague at Zoe, previously shared with B-17 his favorite bean-chili recipe, which he eats for lunch every day. The recipe includes beans and farro, both of which are good sources of protein and fiber.

Becerra-Soberon also recommended making little additions of protein to meals throughout the day, such as by sprinkling on hemp seeds, which contain 31 grams of protein and 4 grams of fiber per 100 grams, or eating almond butter as a snack, which contains about 21 grams of protein and 10 grams of fiber per 100 grams.

Correction: January 8, 2025 — An earlier version of this story misstated Tim Spector’s advice for people wanting to improve their diet. He said they should focus more on consuming fiber than on consuming protein, not that they should consume more fiber than protein.