There are three macronutrients: protein, carbohydrates and fat. Macro comes from the Greek word makros, which means large. Macronutrient refers to large nutrients you can see, and large quantities of which you need to eat every day for optimal health. Protein and carbs contain 4 calories per gram, while fat has 9. Last week’s column was about protein, and next week’s column will be about fat.
Carbohydrates refer to the sugars, starches and fiber found in vegetables, fruit, grains and milk products. At the chemical level they contain carbon, hydrogen and oxygen. They supply 45 to 65 percent of human energy needs, and are an important part of a healthy diet — in spite of what advocates of some non-evidence-based diets claim. In particular, carbs provide energy for the nervous system including the brain, and for muscles.
Carbs can be divided into simple and complex. Simple carbs contain one or two sugars. Fructose in fruit and galactose in milk are examples of single-sugar carbs. Examples of two-sugar simple carbs are table sugar (sucrose), lactose in dairy, and maltose in beer and some vegetables. Simple sugars in whole foods such as fruit and vegetables are fine. However, simple sugars alone (e.g. table sugar or candy); in fruit juice; or added to soda, cookies, cakes, pastries, energy drinks, and other processed foods contribute to many health problems — including obesity, diabetes, cardiovascular disease and cancer. Simple sugars are often disguised on food labels with names such as high fructose corn syrup, organic cane sugar, honey, maple syrup and agave.
Carbs can also be divided into whole (unprocessed) and processed. The latter are bad for you, but there’s a lot of evidence that whole, complex carbs are good for you, even if you have diabetes — in spite of what some dietitians and diabetic educators are still telling people. Whole complex carbs are found only in plants, including whole grains, fruits, vegetables, nuts, seeds and legumes (beans, lentils, chick peas, split peas). These “good carbs” are high in fiber, which supports health-promoting bacteria in our gut microbiome. They help you achieve and maintain ideal body weight. They contain multiple vitamins, minerals and other micronutrients. They have anti-inflammatory properties. They help prevent obesity, diabetes, cardiovascular disease and cancer.
Processed carbs are not good for you. Dr. Fuhrman, author of many books including “Eat to Live,” says “the whiter your bread the sooner you’re dead.” When grains are processed, most of their nutrients are removed. As an example, over a century ago, Europeans introduced white (processed ) rice to Africans who had been doing just fine on natural brown rice. Gradually the Africans started to develop strange symptoms and dying, from what was finally determined to be beriberi, a B-vitamin deficiency. It’s important to get the most nutrients possible per calorie of food you eat — but with refined food you get lots of calories with few to no nutrients. This also applies to foods such as white pasta, white flour tortillas and most chips.
Another problem with refined grains is the high glycemic index. High swings in insulin levels contribute to many health problems, including diabetes. If you eat an apple your blood sugar remains stable — we call that a low glycemic index food. Apple juice (basically flavored sugar water), however, causes an immediate blood sugar spike — we call that a high glycemic index food.
When you’re grocery shopping, how do you tell whether a grain-based product has whole grains and is therefore a healthy choice? You can’t trust the color of the bread — Dr. Fuhrman says “brown bread is just white bread with a tan” — often food companies add raisin juice to produce the brown color. You can’t go by statements on bread wrappers or cereal boxes, such as “multi-grain” or “whole wheat.” Look at the food label and see what the number is for grams of total carbs per serving. Right below that is the number for grams of fiber per serving. You want the total carb:fiber ratio to be 5:1 or less. So, multiply the fiber number by 5, and if the result is higher than the number for total carbs, that product has lots of fiber and whole grains. Also look at the number for sugar per serving size, keeping in mind that 4 grams of sugar is a teaspoon. Finally, look at the number of ingredients, and as plant-based author Rip Esselstyn says, if the number of ingredients is longer than your shopping list, don’t buy it.
Bottom line: Whole (unprocessed) grains are good for us. Sugar and processed carbs are bad for us.
Greg Feinsinger, M.D. is a retired family physician who has a nonprofit: Prevention and Treatment of Disease Through Nutrition. He gives a free presentation at 7 p.m. the first Monday of the month at the Third Street Center in Carbondale; is available by appointment for free consultations (379-5718); and conducts a shop-with-a-doc session at 10 a.m. the first Saturday of the month at Carbondale City Market.