Carbs Explained: Simple vs Complex, and How Many You Need
Carbohydrates are the most misunderstood macronutrient. They have been blamed for weight gain and praised as essential fuel, and the truth sits in between. Carbs are not the enemy — but the type and amount you eat genuinely matter for energy, fullness and health.
What carbs do
Carbohydrates are your body's main quick-access fuel, providing 4 calories per gram. They power your brain and muscles, especially during exercise. Your body breaks most carbs down into glucose for energy, storing some for later. The question is not whether to eat carbs, but which ones and how many.
Simple vs complex carbs
- Simple carbs: sugars that digest fast — found in sweets, soft drinks and refined flour, giving quick energy and quick crashes.
- Complex carbs: starches and fibre that digest slowly — found in whole grains, beans, vegetables and oats, giving steady energy and more fullness.
- Fibre, a type of complex carb, also aids digestion and helps control appetite and blood sugar.
How many carbs do you need?
There is no single right number — it depends on your activity, goals and preferences. A common range is about 45 to 55% of calories for an active person, lower if you prefer a low-carb style. Active people and athletes benefit from more; those cutting weight often do well with somewhat fewer. Prioritise complex, fibre-rich sources whatever your total.
Do carbs make you gain weight?
Not on their own. Excess calories from any source cause weight gain. Carbs get blamed because refined, sugary ones are easy to overeat, but whole-food carbs are filling and perfectly compatible with weight loss.
Should I cut carbs to lose weight?
You can, and some people prefer low-carb, but it is not required — a calorie deficit is what matters. Many people lose weight while eating plenty of complex carbs. Choose the approach you can sustain.
The bottom line
Carbs are fuel, not the enemy — the key is favouring complex, fibre-rich sources over refined sugars and matching your total to your activity and goals. You do not have to cut them to lose weight. Use our free macro calculator to find a carb target that fits your plan.