Regardless of whether your goal is to gain muscle, lose weight, or simply stay healthy, aiming for this range should be a priority. “I always tell people to try to think about fiber like a vitamin or a mineral,” says Dr. Mohr. “There are different types of fiber, and the combination is important.” Soluble fiber, which can be found in foods like beans, sprouts, and broccoli, dissolves in the body and helps reduce cholesterol, lower heart disease risk, and stabilize blood sugar, whereas insoluble fiber from nuts, cauliflower, and potatoes helps to support your digestive system and remove waste from the body.
When it comes to weight loss or even just general health, fiber is especially useful for its effects on satiety and even gut health. “It acts almost like a fertilizer for the bacteria in your body,” says Dr. Mohr.
Not all fat is created equal
The 90-30-50 diet recommends 50 grams of fat per day. While 50 grams may not be right for you, most people could benefit from getting reacquainted with the different kinds of fat, says Amy Lee, MD, chief medical advisor at Lindora. “Just because you’re told to eat 50 grams of fat, what does that really mean? Are you drinking sticks of melted butter? Or are you focusing on things like olive oil?”
“We need fat in our diet to absorb fat-soluble vitamins like vitamins A, D, E, and K, and also to help make some cholesterol, which is used in cellular membranes,” says Dr. Hunnes.
As a general rule, Dr. Hunnes recommends avoiding fats that are solid at room temperature. “Those tend to be the saturated fats, like lard or butter,” she says. The Dietary Guidelines for Americans recommends limiting saturated fats to no more than 20 grams per day. “You want to aim more for plant-based fats—from things like olives, avocado, nuts, and seeds,” Dr. Hunnes says. “Those tend to be the healthier fats—the monounsaturated fats and the polyunsaturated fats, like omega-3s. Those are really the healthy ones.”
What gets measured gets managed
Even if the amounts of protein and fat prescribed by the 90-30-50 diet aren’t the right combination to unlock your own personal goals, there’s something to be said here about the value of a structured diet. “Any time you follow something and you have that structure, you’ll get some benefits,” says Dr. Mohr. “That’s why diets work from the perspective of weight loss, because they give you structure.”
Something that the 90-30-50 diet gets right is its combination of simplicity and specificity (even if the numbers it recommends are simply and specifically wrong for you).
“After over 30 years of helping people achieve better health by eating right, I consistently see that simpler plans work best,” says Peter Brukner, MBBS, FACSM, professor of sports medicine at La Trobe University in Melbourne, Australia. “By focusing on eating real, whole foods, controlling the amount of carbs and fat you eat, and getting enough protein in your diet, you can reach long-term health benefits without feeling too stressed.”
