Food Sense: Gardner's evidence-based rules for eating well
A panel comparing popular diets with American Heart Association guidance found four rules that everyone agrees on, even keto and low-fat vegan: eat whole foods, more vegetables, less added sugar, and less processed food and refined grain, says Stanford nutrition scientist Christopher Gardner, and most Americans follow none of them.
- What to do: Start with the Big Four, then add the Solid Six: beans and other legumes, fruit, nuts and seeds, eggs, fish and yogurt. Eat fermented foods, aiming for about three servings a day.
- Why it matters: In a 12-week crossover trial in people with prediabetes or type 2 diabetes, a well-formulated keto diet and a Mediterranean diet both cut HbA1c and weight (about 6 kg), but keto lowered triglycerides more and raised LDL. Keto and paleo ranked lowest against heart association guidance.
- How to apply it: Judge studies by the foods eaten, not the diet label, check who was studied and for how long, and wait for replication. Pick the pattern you can sustain, and add resistance training if you eat plant-based, especially after 70.
- Metrics: A garlic trial with 200 adults over 6 months and about 35,000 sandwiches found no LDL drop. In the fermented food and fiber trial, 20 of 90 inflammatory markers fell, but the primary composite score did not change.
- Tools: Function lab tests such as MMA for B12 function and magnesium, and IM8 multinutrient.
- Risks: Some fermented foods are high in sodium. Older adults on a vegan diet lost thigh muscle in one 12-week trial, and their protein intake dropped by 20 to 30 grams a day.
- Exceptions: Eggs are fine for most healthy people, but cholesterol may matter more for those who are sick and eat many animal products.