So, which foods raise insulin? Well, those are your refined sugars and carbohydrates. “Sugars and highly refined, high-glycemic index carbohydrates are a mistake,” he notes. “If anything causes the chronic diseases that beset us, heart disease, it’s sugar first and refined grains second. I would avoid those if I wanted to be as healthy as I could.”
Of course, that means he nixed the white bread and pasta. However, when he was trying to lose stubborn weight, he lowered other types of carbs, like sweet potatoes and beans, and legumes. “[Sweet potatoes] may be fine for some people, but they’re not fine for me, and if I were trying to lose a significant amount of weight, I wouldn’t include them in the diet,” he explains. “They still have a significant amount of carbohydrates and they’re easy to overeat.”
That’s not to say he cut all healthy carbs cold turkey (leafy greens do contain carbs, too, after all), but he certainly focused more on a high-fat, low-carb diet (aka, the building blocks for keto). Research backs this up, too, as a systematic review found that individuals who followed a very-low-car, high-fat ketogenic diet achieved greater weight loss (and kept it off long-term) than those who followed low-fat diets.