Protein might build muscle, but no amount of steamed chicken will get you ripped on its own. “No matter what anyone says, you need carbs after training,” says Glenys Jones, nutritionist at the Medical Research Council. “The chains of carbon, hydrogen and oxygen all break down into glucose, our essential fuel.”
“If you feel fatigued after training, with heavy legs and low motivation, it’s often because you’re in a carb-depleted state,” says sports nutritionist Becky Stevenson. Carbohydrates are also essential for everyday living – whether lifting your mood or making sure you don’t lose your hair. Here are the top 11 reasons to keep starching on.
1. Stabilise sugar levels
Your body stores some unused sugar as glycogen in the liver and muscles, but converts the rest to fat. “Low GI carbs – oats, beans and wholemeal bread – avoid that fat-storing process by breaking down slowly for a steady rise in blood sugar,” says Stevenson. The Food Standards Agency advises a third of your daily calories should be starchy; two slices of toast and a sandwich gets you halfway there.
2. Aid digestion
Low-carb diets cause bad breath and low energy but the real curse of Atkins’ dogma is constipation. “Carbs are our only source of fibre – they’re a physical bulk that gets things moving,” says Jones. Your best weapon here is bran: one bowl of All-Bran contains 10.3g of dietary fibre, well over half your daily needs.
3. Increase your endurance
For intense exercise, forget the low GI rule – temporarily. “Sugary carbs deliver an instant hit of energy,” says ultra-running GP Dr Andrew Murray. “For any activity longer than 60 minutes, you need between 30-60g of carbs per hour.” A banana packs 36g.
4. Beat infections
A carb-deficient diet can send cortisol levels soaring, say researchers at Loughborough University. “The stress hormone then compromises your immune system,” says Stevenson, which increases the likelihood of you calling into work sick. Keep breathing clear with immune-boosting beta-carotene, found in sweet potatoes.
5. Speed muscle recovery
A post-workout carb fix helps release insulin, putting you into an anabolic, muscle-building state, says the American Journal of Clinical Nutrition. But it only works when you take in protein and fat, too, explaining why 470ml ofchocolate milk – which hits all three – proved to be the best recovery drink in a University of Connecticut study.
6. Lower blood pressure
While meat sends blood pressure soaring, plant foods lower it, say researchers at the University of Minnesota. Their findings are backed up by the American Journal of Clinical Nutrition, which reported that wholegrains alone can slash hypertension by 19%. Ease the pressure with quinoa – 80g provides almost half your RDA of blood vessel-relaxing magnesium.
7. Maintain healthy hair
All that extra energy gives your follicles a boost, too: of two groups who spent six months on either a low-carb or a low-fat diet, the latter were 24% less likely to report hair loss, say Philadelphia University researchers. It could be down to the nutrients in fortified cereals: just 50g of cornflakes gives you your full RDA of cell growth-promoter folic acid.
8. Boost your brain power
“Low blood sugar deprives your brain of glucose, leaving you fluffy-headed and weak,” says Jones. The good news? Mental stimulation is packaged in punnets: scientists have linked carb-rich berries to reduced oxidative damage in the brain, which follows earlier research that a blueberry smoothie maintains concentration for up to five hours.
9. Keep your cool
Low-carbers swiftly drop pounds – if they can handle the heat. “Although 10g of carbohydrates provides 2.5 fewer calories, it takes more energy to metabolise a gram of protein, increasing the heat your body produces,” according to Murray. Avoid the infamous meat sweats with brown rice – 180g contains 83mg of body temperature-regulating magnesium.
10. Lift your mood
Tryptophan, the amino acid that boosts serotonin levels and makes you feel great, is found in protein-rich foods like egg, turkey and cheese. “But you need to serve these with high-carb foods to feel the effects,” says Jones, who recommends partnering a grilled turkey steak with a handful of wholemeal pasta. Making it for two could boost those feel-good hormones even further.
11. Fight cancer
Your protein-rich diet may be getting you stacked but it could also be putting you at risk of lung and bowel cancer, according the Annals of International Medicine. Combat it with super-carb broccoli, and boost the green stuff’s cancer-fighting abilities with a probiotic yoghurt. A University of Illinois study found good gut bacteria up your intake of broccoli’s big ‘C’ fighting compound sulforaphane.
Get the balance right
Eat too many carbs, though, and you could find your waistline expanding. Sports nutritionist Becky Stevenson reveals how much is enough…
Light activity (less than one hour per day) 4-5 grams of carbs per kg of weight
Light to moderate (one hour per day) 5-6g
Moderate (1-2 hours per day) 6-7g
Moderate to heavy (2-4 hours per day) 7-8g
Heavy (more than four hours per day) 8-10g