Energy and protein for active people

Which carbohydrates give the best energy for activity?

Wholegrain, higher-fibre starchy foods, along with vegetables, fruit and pulses, are the best everyday sources of carbohydrate. Health organisations advise getting most of your carbohydrate from these foods^1,2. Starchy foods are our main source of carbohydrate and a good source of energy, and they supply many other nutrients too¹.

• Choose wholegrain versions of bread, pasta, rice and cereals where you can. Wholegrain foods are digested more slowly than refined grains, so they can help you feel full for longer¹.
• Eat potatoes with the skin on for more fibre. Potatoes are a good source of energy, fibre, B vitamins and potassium¹.
• Pasta is a healthy base for a meal. It contains iron and B vitamins, and wholewheat pasta has more fibre¹.
• Check cereal labels. Many refined cereal products can be high in added salt and sugar¹.
• Treat fruit juice as an occasional drink. Most fruit juices, even without added sugar, contain significant amounts of free sugars, so they should be limited².

If you have diabetes, carbohydrate needs differ from person to person. Get individual advice from your doctor, a dietitian or a diabetes organisation, especially around exercise.

What role does fat play in endurance activity?

Fat is one of the body's main fuels for longer, steady activity, and your body uses it together with carbohydrate rather than one replacing the other^3,4. In sustained activity, fat supplies fatty acids that the muscles burn for energy. This helps keep you going and slows the running down of your stored carbohydrate³.

The mix changes with effort. Fat supplies more of the energy at lighter effort, and carbohydrate takes a bigger share as effort rises⁴. Fat alone can only sustain a moderate effort, so your body can't rely on fat alone at harder intensities⁵. That is why the body draws on both fuels, and why there's nothing you need to do to switch fat use on.

In athletes, very high-fat diets raised fat use during moderate exercise, but they also reduced the body's ability to use carbohydrate and lowered power output at higher intensities⁴. If you're thinking about a very high-fat or low-carbohydrate diet, talk it over with your doctor or a dietitian first. Cutting out a major food group can mean missing nutrients.

How much protein do you need to support your muscles?

For healthy adults over 65, expert groups recommend at least 1.0 to 1.2 g of protein per kg of body weight per day^6,7. For older adults with an acute or chronic illness, the advised range is 1.2 to 1.5 g/kg/day^6,7. Older people who are exercising and otherwise active are advised to take in 1.2 g/kg/day or more⁶.

To see what this means for you, multiply your weight in kg by the figure. For adults generally, protein at 10–15% of daily energy is usually enough. That is roughly 50–75 g for someone of healthy body weight eating about 2000 calories a day. It may be higher for people actively building or maintaining muscle².

Protein works best alongside strength activity. Resistance exercise produces much larger gains in muscle strength and mass than added protein does⁸. Experts also recommend daily activity, including resistance and aerobic exercise, for all older people for as long as possible⁷.

For healthy adults doing resistance training, the standard 0.8 g/kg/day may be too low if you want to gain strength and muscle. Intakes above about 1.6 g/kg/day added no further gain, so treat that as a rough reference point, not a target⁸. For inactive adults aged 60 and over, extra protein on its own tends not to add much muscle, and results for strength and physical performance are mixed. The best intake for inactive people isn't clear yet⁹.

If you have an illness, are underweight or have lost weight without trying, ask your doctor or a dietitian what protein amount suits you.

When to check with a health professional

If you're starting exercise after a long break, it's always a good idea to see your doctor first.

For an injury or a health condition, see a health professional, such as your doctor or a physio. For advice on food that suits your health, medicines and budget, a registered dietitian or your doctor can help. If you have diabetes or another long-term condition, check with them before changing how much carbohydrate or fat you eat.

Call your local emergency number for chest pain or pressure (or pain spreading to the arm, neck, jaw or back, especially with sweating or feeling sick), severe breathlessness, fainting or collapse, signs of a stroke, a serious injury, or someone who isn't safe.

For a sore muscle or joint, ease off and build up slowly, and see a doctor or other health professional if it persists or gets worse. Unusual tiredness isn't something to push through, so get it checked by a doctor.