Summary
Highlights
To reduce the glucose and insulin effect of rice, it is better to eat rice that has been cooked, cooled, and then reheated. This process creates resistant starch, which is not absorbed by the body, leading to a 20% reduction in glycemic impact. Dr. Fung freezes individual portions of cooked rice for later use.
For potatoes, eating them cold, like in a potato salad, also reduces their insulin effect due to resistant starch. Adding vinegar to carbohydrates further enhances this effect. Vinegar (acetic acid), lactic acid from fermented foods (kimchi, sauerkraut), and citric acid (lemon juice) inhibit the amylase enzyme, slowing down glucose absorption and reducing blood sugar and insulin spikes. The choice of vinegar matters, as some, like balsamic, can be sugary.
Eating carbohydrates last, after proteins and vegetables, can significantly reduce blood sugar and insulin spikes. This is because proteins and fats slow down stomach transit time, meaning glucose is absorbed more slowly into the bloodstream, leading to a more gradual rise in a blood sugar and insulin, with some studies showing a 50% lower insulin response.
Green tea helps in weight loss by blocking the COMT enzyme, which slightly increases sympathetic tone, leading to decreased hunger. It also contains caffeine, which stimulates metabolism, and is a sugar-free alternative to sugary beverages. Green tea's benefits may be more pronounced in individuals with certain genetic variations.
Evidence suggests the brain can directly signal the liver to produce sugar, particularly under stress, to provide quick energy. Additionally, the gut microbiome can influence stress eating. Molecules produced by certain gut bacteria in individuals with metabolic diseases like diabetes can lower the stress-eating threshold, creating a cycle where poor metabolic health exacerbates stress-induced eating.
Dr. Fung criticizes oversimplified models of weight loss, such as 'calories in, calories out' or 'low-fat diets,' arguing that they ignore the complex interplay of digestion, absorption, hormones, and individual differences. He emphasizes that weight gain is a complex disease influenced by numerous factors, and effective solutions require a nuanced understanding beyond simplistic calorie counting.