A dietitian breaks down which carbs fuel your body and which ones sabotage it—plus the myths that refuse to die.
Why carbs became so confusing
When you’re trying to lose or maintain weight, advice about carbohydrates comes from everywhere. Some—beans, legumes, fruits, whole grains, vegetables—contain vitamins, minerals and fiber that fuel your body. They’re less likely to spike blood sugar, giving you sustained energy. But should you avoid all of them or just certain ones?
Dietitian Julia Zumpano clears up the confusion and dismantles myths that keep circulating despite evidence.
Understanding simple versus complex carbohydrates
Carbs are a macronutrient found in certain foods and drinks. Fiber, sugar and starch all count as carbs. They fall into two categories: simple and complex, determined by chemical structure and digestion speed.
Simple carbs digest easily, causing blood sugar to spike. Refined sugars like white sugar and added sugars in soda fall here. But naturally occurring sugar in fruit and milk provides vitamins, minerals and fiber. Just watch your portions.
Complex carbs digest more slowly, releasing steady sugar that keeps you fuller longer and provides consistent energy. Look for unrefined whole grains rich in fiber and nutrients like vitamin B.
Your body actually needs carbohydrates
Yes, you need carbohydrates. The right types and amounts provide energy, protect against disease and help control weight. Carbohydrates are your body’s main energy source, providing fuel to get through demanding days. The question isn’t whether to eat carbs but which ones to choose.
Carbs make you gain weight
People often blame carbs for weight gain, but complex carbohydrates like whole grains aren’t fattening foods. This myth likely stems from how they affect insulin. Eating carbohydrates raises blood glucose and prompts insulin release, which redirects glucose to cells.
The type and quantity of carbs you eat cause weight gain—not carbohydrates themselves. Many contain excess calories and sugar. Desserts, white bread, rice, pasta and snack foods like chips are refined versions stripped of fiber and protein, making glucose levels spike quickly.
Those containing fiber like brown rice or protein like legumes raise blood glucose more slowly, require less insulin and keep you satisfied longer. But even complex versions need moderation.
For weight loss, limit carb intake to about one cup per meal—roughly the size of a coffee mug. Keep intake around 40% to 45% of total calories. Healthy fats should make up 30% to 35%, and lean proteins should cover the remaining 20% to 30%.
Only white foods contain carbohydrates
Confusion exists about which foods even qualify. People often think only rice, bread, pasta, potatoes, sweets and sugary drinks count. The reality extends far beyond white foods.
High-carb options also include sweet potatoes, corn, peas, winter squash, grains like millet and barley, oats, quinoa, dried beans, brown and wild rice, yogurt, milk and fruit. High-fiber options like legumes and whole grains provide more nutrients than refined grains and sweets.
All white foods deserve avoidance
White foods like processed grains and sweets rank higher on the glycemic index, quickly raise blood sugar and cause inflammation. But other options considered white can be essential to good health.
They contain phytonutrients, have antioxidant activity and support immunity. Potatoes have a bad reputation but are great sources of potassium, fiber and vitamin C. Stick to half a medium potato, which weighs about a quarter pound.
Other nutrient-rich white foods include cauliflower, nuts and seeds, onions, garlic, beans, jicama, ginger and apples.
Fruit is bad because it’s high in carbohydrates
People claim fruit has too much sugar. The truth is that fruit is nutrient-dense. Along with fructose, fruit provides fiber, vitamins, minerals and phytonutrients.
Many fruits today are far larger than recommended portions, which makes daily calories add up fast. One serving of hand fruit like an apple or orange is the size of a tennis ball. A four-inch banana is one serving. So are 17 small grapes.
Fresh or frozen fruit without added sugar beats fruit juice. Fruit juice concentrates fructose but lacks fiber. If you love fruit juice, limit portions to four ounces.
Pick options bursting with fiber, protein, vitamins and minerals. Skip those devoid of nutrients. Carbohydrates play an important role in a healthy, balanced diet when you choose wisely.