Note: This is the second in a series about Macronutrients: Protein, Carbohydrates & Fat

Are you confused about which carbohydrates are healthy, which aren’t, and how many carbs are just too many? If so, you’re in good company.

Carbs get a bad rap. Some of that’s deserved, but they aren’t all bad, and they’re important for other reasons. Let’s sort it out.

Photo credit: diagnosisdiet.com

The lowdown on carbs

Carbs are one of three macronutrients, along with protein and fat, which our bodies need in large quantities. By contrast, micronutrients, chiefly vitamins and minerals, are the smaller compounds our bodies need.

Carbs’ main job? Energy. Most carbs turn to glucose in the body, which our cells use as fuel to create energy. That’s important. However, too much glucose can lead to a myriad of health problems. (More on that below.)

Healthy carbs vs. unhealthy carbs

Most chat about carbs refers to highly-processed foods such as bread, sugary drinks and snacks, pizza, pasta, cereal and chips, and also whole foods like potatoes, rice and oatmeal.

But did you know that all the plants we eat — fruits, vegetables, grains and beans — are carbs? What varies greatly among them are the carb types and amounts.

Take potatoes, carrots, berries and cucumbers. All four are made up almost entirely of carbs (vs. protein or fat), but while total carbs in potatoes is high, in cucumbers it’s quite low.

Generally speaking, whole food sources of carbs are nutritious because they contain fiber, vitamins and minerals. But quantity matters. Even the healthiest sources of carbs, when eaten excess, can raise blood sugar and have ill effects on health.

Your body makes insulin, which shuttles glucose into cells. But when there’s more glucose on board than our cells can use for energy, they stop letting it in. This starts the process of insulin resistance.

Excess glucose in the blood can be stored as triglycerides in fat cells. But over time, insulin resistance can lead to type 2 diabetes, high blood pressure and various other inflammatory conditions.

Types of carbs

The Nutrition Facts panel on U.S. food labels lists Total Carbohydrate, Fiber and Total Sugars (including any Added Sugars).

Sugar comes in many forms, but most convert to glucose in the body. Sugars range from high fructose corn syrup and white sugar to maple syrup, agave and honey.

If a sugar naturally occurs in a food, such as the lactose in milk (straight from the cow), it’s listed on the Total Sugars line. For chocolate milk, right, you see most of the sugars are added.

Starch is the one carb missing from food labels. It comprises the bulk of breads and other flour-based foods, as well as potatoes and rice. Starch converts to sugar in the body — primarily glucose — and triggers blood sugar spikes.

Unlike sugar and starch, fiber doesn’t fully digest and instead plays many important roles, as with gut health, which in turn supports metabolic and heart health. (Read more about fiber here.)

How much is too much?

The magic question! How many carbs you need for energy — or can tolerate without negative effects — depends on your body size, activity level, age, metabolic health and other factors. I help my clients answer this question.

Low-carb diets

Carbs make up more than 50% of calories for most Americans.

By contrast, a “low-carb diet” limits carbs to 25% or less of total calories (= 100-150 g carbs/day). A very low-carb, or ketogenic, diet keeps net carbs (total carbs minus fiber) between 20-50 g a day. Most people who achieve ketosis — a metabolic shift toward using fatty acids for fuel — have eliminated (or nearly so) all added sugars and starches from their diet.

A low-carb diet is generally safe and helpful for people wanting to lose weight and/or to lower their blood sugar. However, the safety and benefits of a keto diet are situation specific.

Practical tips for cutting carbs

• Create meals with a palm-sized amount of protein, enough colorful veggies to fill half your plate, healthy fats spread throughout, and a 1/2 cup or less of starchy carbs

• Trade out processed carbs like those listed above for whole food carbs, which are richer in nutrients. Substitute cauliflower rice for regular rice (or mix them 50/50); use spaghetti squash or zucchini noodles in place of pasta

• Woh, no pasta, you ask? Zucchini noodles? Ok, well … lots of people love them, myself included. But if that’s a deal breaker, eat half the amount of your favorite pasta

• Limit high-starch foods and don’t eat them solo. For example, a half bagel with 20 g of carbs will spike blood sugar, whereas an egg scramble with 20 g of carbs dispersed between high-fiber broccoli, tomatoes and mushrooms will produce only a modest (and normal) rise in blood sugar

• Find middle ground. Say you like cheese and crackers in the afternoon. By adding cucumber slices, carrot sticks and a scoop of hummus, then reducing the crackers by half, you get a more nutritious, filling (and tasty!) snack that won’t spike blood sugar

• Check the cronometer app to estimate the carb counts on your favorite foods

• Love to bake? Almond and other nut flours are lower in carbs than flours made from wheat, rice and other grains. And by trading out some of your added sugars for fruit, such as banana or apple, you’ll boost fiber and other nutrients

Confused about carbs? I got you!

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