Once you've used up all your carbs, your body starts to use fat as its main energy source. Your brain, however, needs glucose. If your body lacks carbohydrates, glucose is formed from proteins. The metabolism of fat that occurs when you lack carbohydrates forms ketone bodies, which the brain can also use as energy. Ketosis – the accumulation of ketone bodies in your system – also diminishes your appetite, which in turn reduces your energy intake and increases weight loss.
Low-carb diets are not recommended in the long-term.
Several studies have shown that, compared to the standard recommended diet (a reduction in fat and sugar, more vegetables and increased exercise, etc.), a diet very low in carbohydrates poses at least the following risks:
• insufficient fibre intake
• your intake of some vitamins and minerals may be insufficient due to your restricted diet
• increasing exercise may be difficult due to increased fatigue.
Replace poor sources of carbs with good ones
Instead of completely avoiding carbohydrates, you should focus on their quality. Choosing wholegrain products, fruits and vegetables will greatly improve the quality of your diet. It's a good idea to significantly reduce sugar and refined grain products.
Exercisers need carbohydrates
Carbohydrates are the first to be burnt – your reserves will start to wane in only 1–2 hours. Carbs help sportspeople and exercisers to recover. An increase in foods containing carbohydrates – and in particular multi-chain, insoluble carbohydrates (fibres)– is recommended, as they contain not only energy, but also many other useful nutrients and important compounds.
Recommended carbohydrate intake
Nutritional recommendations state that carbohydrates should account for about half of your daily energy intake. This means that, for example, an average 2,000-calorie diet should contain about 250 g of carbohydrates.
Sportspeople require even more carbs: Recommendation:
– sportspeople 5–6 g / kilo of bodyweight / day
– endurance athletes 6–8 g / kilo of bodyweight / day