Much info about low-carb diets is misleading
DEAR DR ROACH — I recently had my yearly physical with my primary care doctor of 10 years. I am a male, 75, who is 5 feet, 10 inches tall and weighs 152 pounds. He sent me my lab results and commented: “Your A1C (5.8) was in the pre-diabetic range of 5.8-6.4. Remove all grains/ breads/carbs/sugars and processed food from your diet and recheck this level in 6 months.” I read up on low-carb diets and found that low-carb diets are rich in saturated fat and cholesterol, which might raise bad cholesterol and increase risk of heart disease. My previous A1C tests with my primary care doctor have shown my A1C between 6.2 and 6.0 over the past five years. I would appreciate your opinion on all of this. — K.C.
ANSWER — The advice you received from both sides about low-carbohydrate diets was both right and wrong, in my opinion.
I mostly agree with your doctor, but his answer needs some context. Cutting down greatly on simple sugars and starches, including grains, breads and pasta, is likely to improve your A1C (a measure of blood sugar over time). You do not need to lose weight, so that isn’t an issue for you. Personally, I don’t “order” people to reduce starches and sugars to zero, as that seems to me unnecessarily restrictive. Further, by having limited amount of starches in combination with protein and healthy fat, you can limit the rise in blood sugar associated with their consumption.
The information about low-carb diets is, at best, misleading: It’s possible to change a high-starch diet to a much healthier diet without eating much (or any) meat or eggs. There are many plant-based sources of protein to fulfill the body’s needs. People also may eat modest amounts of fish, skinless poultry or lean meat without increasing heart disease risk. Saturated fat comes mostly from animal sources (and to a lesser extent tropical oils, which I do not recommend), and a healthy plant-based diet uses mono- and polyunsaturated fat, which has been shown to reduce cholesterol numbers and heart disease risk.
The plant-based diet I recommend is largely carbohydrate, but not starchy. Unlike processed starches like white rice and white flour, vegetables and legumes are high in fiber, which helps people feel fuller and attenuates the blood sugar response. Similarly, fruits are high in sugar, but whole fruits do not increase A1C the way added sugars do.