The health outcomes associated with low-fat and low-carbohydrate dietary patterns are primarily determined by the quality of the food sources consumed, rather than by the specific ratios of macronutrients alone.

Study: Effect of Low-Carbohydrate and Low-Fat Diets on Metabolomic Indices and Coronary Heart Disease in U.S. Individuals.

Whether you eat low-carb or low-fat, what you eat matters more than how much carb or fat you cut — eating healthy foods like veggies and whole grains helps your heart, no matter which diet you pick.

Study: Associations between overall, healthful, and unhealthful low-fat dietary patterns and breast cancer risk in a Mediterranean cohort: The SUN project.

The study found that eating low-fat foods isn’t healthy unless they’re good-quality foods like whole grains and vegetables—eating low-fat junk food was linked to higher cancer risk. So it’s not just about fat, but what kind of food you eat.

Study: Habitual low carbohydrate high fat diet compared with omnivorous, vegan, and vegetarian diets

The study found that people on low-carb, high-fat diets got sicker not because they cut carbs, but because they ate too much bad fat and not enough fiber — so what you eat matters more than just how much fat or carbs you have.

Study: Dietary and Policy Priorities for Cardiovascular Disease, Diabetes, and Obesity: A Comprehensive Review

The study says what you eat—like veggies, nuts, and whole grains instead of processed meats and sugary foods—is what really matters for health, not just whether your diet is low-fat or low-carb.