Carbohydrates
Have you ever believed whacky things like ‘’White potatoes are full of starch; they will make you fat", "White bread makes you fat", "If you eat carbohydrates before bed, you will store them as fat because the energy isn’t being used", or "Cutting out carbohydrates makes you burn more fat’’? If you have never believed any of these whacky myths before, congratulations! You are less gullible than me!
Although carbohydrates are not essential to survival, they should be included for optimal health. The brain and the central nervous system use glucose as the primary fuel and require a continued supply. When we cut out carbohydrates, fat can be converted to glucose by a process called gluconeogenesis, but I’ll try not to geek out and bore you, so we will stop there.
Carbohydrate requirements depend on the individual and their goals. Here are just a few examples (these requirements vary from person to person):
Values per kg:
Performance 3-10g
Fat loss: 1-3 g
Muscle Gain: 2–6 g
Health 1-4g
What are the main benefits of carbohydrates?
Satiety and palatability: Many sources of carbohydrates are very filling; for example, white potatoes are rated one of the highest foods on the satiety index (the state of being full).
Maintain digestive health: carbohydrates provide us with both dietary fibre and resistant starch. Dietary fibre controls blood sugar levels, adds volume to our meals at a low energy cost, and maintains bowel health. Soluble fibre slows digestion time, and insoluble fibre enhances digestion time. Resistant starch contains prebiotics, which are beneficial for our gut. However, caution should be taken for individuals with GI issues. (Zaman&Sarbrini,2016)
Sleep: Carbohydrates increase tryptophan, an amino acid precursor to serotonin and melatonin production. Low-carb diets can negatively impact sleep quality. (Afaghi A. et al., 2007)
Where did the myth of carbohydrates bringing you out of a fat-burning zone originate?
Insulin does switch off fat oxidation, but fat oxidation is not the same as fat loss. When we consume carbohydrates, the body will stop oxidising fat in order to oxidise carbohydrates. But what actually matters at the end of the day is the difference in calories in calories out.
What makes people believe low-carbohydrate diets are superior?
Often, they lead to increased protein intake. Increased weight loss is not fat loss; we know 1g of carbohydrates equals 3g of water, and carbohydrates are stored in the muscle as glycogen (15 g/kg). It's easy to implement with minimal support. Appetite control is important for some individuals.
Summary-
Low-carbohydrate diets aren't superior for fat loss in healthy individuals. The ketogenic diet can be effective for people who suffer from seizures (epilepsy).
Low-carbohydrate diets have their purpose; we should not be all for them or all against them, like any diet.
If your goal is performance, a low-carbohydrate diet will affect performance, so it should be included in the diet.
Reference:
https://www.ncbi.nlm.nih.gov/pubmed/25582732 (Prebiotics)
http://www.ernaehrungsdenkwerkstatt.de/fileadmin/user_upload/EDWText/TextElemente/Ernaehrungswissenschaft/Naehrstoffe/Saettigung_Lebensmittel_Satiety_Index.pdf (Satiety index)
https://www.ncbi.nlm.nih.gov/pubmed/17284739 (Sleep)