How many carbs do you need, and does it change with age?

"How many carbs should I eat?" is one of the most searched nutrition questions, and the answers online range from almost none to more than half your plate. This is the fourth article in our carbs series. It sets out what the official guidelines say, and what genuinely changes as we get older, especially for women.

New to the series? Start with Are carbs bad for you?

The short answer

There isn't a single right number. Guidelines give a minimum and a healthy range, and the quality of the carbs matters more than the exact amount.

• Minimum: 130 g of carbohydrate a day for adults and children over 1. This is set by the US National Academies, based on how much glucose the brain needs.
• Healthy range: 45 to 65% of your daily energy, according to the same body. WHO has said a wider range, about 40 to 70%, can be part of a healthy diet.
• Fibre: at least 25 g a day for adults (WHO).

As we covered in part 1, a large 2018 study found the lowest risk of early death at about 50 to 55% of energy from carbs, with higher risk at both very low and very high intakes.

What that looks like in practice

The percentages are easier to picture as grams:

Most of us don't count grams, and you don't need to. A simpler guide: fill half your plate with vegetables, a quarter with protein, and a quarter with starch, ideally whole grain. Add fruit as a snack or dessert.

Does it change with age?

The minimum and the healthy range stay the same through adult life. What changes is how much total food you need, how much protein matters, and how your body handles blood sugar.

Children and teens

The same 130 g minimum applies from age 1, and growing, active children often need more. WHO recommends 15 to 25 g of fibre a day for children, depending on age. The biggest win for most families is cutting sugary drinks and sweets, not starch.

Pregnancy and breastfeeding

Needs go up: the recommended minimum is 175 g a day in pregnancy and 210 g while breastfeeding, because the baby's brain and breast milk both depend on glucose. Don't cut carbs below these levels without your doctor's guidance.

Your 20s to 50s

Good news first: a large 2021 study found that metabolism, adjusted for body size, stays steady from about 20 to 60. If weight creeps up in midlife, it's more often less activity and less muscle than a slower metabolism. So the main lever is carb quality and portion size, plus staying active. See Health tips for women over 40.

Menopause

This is where women do see a real change. Studies following women through menopause found that the transition itself is linked with more fat around the middle (visceral fat) and lower daily energy use, separate from ageing. Fat around the middle is closely tied to insulin resistance, when the body handles blood sugar less well.

That doesn't mean you have to give up carbs. It does make carb quality more important:

• Choose whole grains, beans and lentils over white bread and sugary foods.
• Pair carbs with protein and vegetables at every meal.
• Keep up strength training, which helps your muscles use glucose.
• If you've been told you have prediabetes or insulin resistance, a lower-carb approach can help; talk to your doctor about what suits you.

After 60

From around 60, daily energy needs start to fall slowly. Many older people also eat less overall, so every meal needs to count. Protein becomes more important: an international expert group recommends 1.0 to 1.2 g of protein per kg of body weight a day for people over 65, more than the standard adult amount, to help keep muscle. In practice, that means making sure carbs don't crowd protein off the plate.

Who might do better with fewer carbs?

Lower-carb eating has the best evidence for people with type 2 diabetes or prediabetes; see Supplements and type 2 diabetes: what lowers blood sugar. Some people also find it helps with appetite and weight. If you go lower-carb, build it on vegetables, nuts, seeds, fish and legumes rather than mostly meat and fat: the 2018 study linked plant-based low-carb eating with lower risk, and animal-based low-carb eating with higher risk.

Frequently asked questions

Do I need to count carbs?
Not unless you have diabetes or a doctor has advised it. The plate guide above works for most people.

Is 100 g of carbs a day too low?
It's below the official minimum for adults. Some people eat this way for a time, but if you plan to stay this low, do it with advice from your doctor or a registered dietitian, especially if you take medicine for blood sugar.

Do men and women need different amounts?
The minimum and the percentage range are the same. Men usually need more total energy, so the grams come out higher.

Next in this series

• Simple carb swaps that work in a South African kitchen

The sources

• Institute of Medicine (2005). Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press. View →
• World Health Organization (2023). Carbohydrate intake for adults and children: WHO guideline. View →
• Seidelmann SB et al. (2018). Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis. Lancet Public Health 3:e419–e428. View →
• Pontzer H et al. (2021). Daily energy expenditure through the human life course. Science 373:808–812. View →
• Lovejoy JC et al. (2008). Increased visceral fat and decreased energy expenditure during the menopausal transition. International Journal of Obesity 32:949–958. View →
• Bauer J et al. (2013). Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE study group. Journal of the American Medical Directors Association 14:542–559. View →

Find out more

• Are carbs bad for you? Good carbs vs refined carbs explained
• How refined carbs affect your blood sugar, energy and cravings
• What's really in supermarket bread and pasta?
• Health tips for women over 40: what actually matters

This article is general information, not medical advice. If you are pregnant or breastfeeding, have diabetes or another medical condition, or take medicine that affects blood sugar, speak to your doctor or a registered dietitian before changing how much carbohydrate you eat.

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