Good Carbs, Bad Carbs
Carbohydrates are the sugars and starches that make up part of our food. The digestible carbs are the quickest forms of energy for your body to use. (Dietary fiber is also a carb, but it helps to clear out your gastrointestinal tract rather than contributing energy.)
Carbohydrates are sometimes divided into “good” and “bad” by their source or processing. Generally “good” or “bad” refers to whether a carb has “redeeming qualities” — carbs from vegetables, whole fruits, and whole grains include dietary fiber, and usually get a halo for this reason. For people who react very abruptly to refined sugar, like candy (with a “sugar high”), getting carbohydrate in these other forms leaves them feeling fuller and more satisfied for longer, because it is digested more slowly, and the fiber helps create a sense of fullness. (By contrast, refined sugar products, like soda or candy — especially if they are fat-free — are more likely to just whet your appetite for more of the same.)
Fast Carbs, Slow Carbs
Tim Ferriss popularized the description “fast” and “slow” to refer to something called the glycemic index — a measure of how quickly carbs are used by the body. Fast carbs are generally more refined and more toward the sugary end of the spectrum. Slow carbs are fiber-rich legumes and vegetables, and fast carbs are just about everything else. If this division helps you focus your eating pattern on filling foods that help you meet your overall calorie goals, then by all means use it, but Ferriss’s “Slow-carb diet” is quiet restrictive. (For example, it bans dairy, except cottage cheese, as well as grains, fruits, and potatoes — which can be fine sources of carbs with fiber.) Ferriss promotes this pattern for rapid weight loss, but you may have more luck finding a middle ground you can stick with for the long haul, even if it means slower weight loss.
What Do I Need to Know?
Carbs are often ground zero for deliciousness. Pastries and cakes, candy, and foods like french fries (which up the ante by adding high-calorie fat) have lots of calories and are easy to eat a lot of. They make it harder to keep track (and take control) of your total calories. Carbs aren’t all evil — although the mushrooming library of low-carb diet plans sometimes makes it sound that way — they are just an easy target to help people control calories, because carb-heavy foods have so many and are so tempting.
Carbs are present in vegetables, fruit, and in whole grains, too, though, and many carb-rich foods are good choices in a healthy diet. Just be honest with yourself about potential “trigger foods” — I myself find it helpful to avoid white flour, although I eat a lot of carbs in general — and fill up on satiating, “nutrient-dense” (lots of good stuff) foods like vegetables (as well as protein) before you reach for the treats. (And yes, french fries are a treat!)
You can find more information about putting different foods together for healthy eating from Harvard’s Healthy Eating Plate.