I don’t know about you, but there is a lot about carbohydrate consumption that I don’t understand. We all know that age-old diet advice which tells us that to lose weight, we should cut down on how much carbohydrate we eat. But, if that is the case, what is the deal with these ‘High-Carb Diets’ that are thought to help weight loss? And, what if I don’t want to lose weight; how much carbohydrate should I be eating then? And what about eating carbs before bed; that’s bad, right? These are just some of the many carb-related-questions that have been bugging me this week, and so I thought I’d do a little investigating and tell you all what I found out.
Vegan French Toast: My favourite kind of carbs
Carbohydrates are one of the most important sources of energy for the body. When I think of ‘carbs’, I typically think of bread, pasta, rice etc. But these are not the only type of carbohydrates. Plant foods are a particularly important source of dietary carbohydrate and many fruits and vegetables are full of the stuff. So why have ‘carbs’ got a bad name?
Carbohydrates that have a high glycaemic index (GI) produce a spike in blood sugar when we eat them. Frequent spikes in blood sugar can eventually lead to the development of ‘insulin resistance’; one of the key components of Type II Diabetes. Foods with a high GI are also digested relatively quickly, which means that we don’t stay full for long. This means that we are likely to feel hungry again and may lead us to consume more calories soon after. Foods with a high GI include white bread, refined-grains and sugars.
Me, about to drink a big ol’ carb smoothie (bananas + oats + almond milk + cacao)
Foods with a low GI are digested more slowly and do not cause large fluctuations in blood sugar. This means that we stay fuller for longer. But, the really important thing about these foods is that they are high in ‘dietary fibre’. Dietary fibre is the indigestible portion of food which interacts with our digestive system and affects how other nutrients and chemicals are absorbed by the body. For example, certain types of dietary fibre attract water during digestion which slows the emptying of the stomach and helps blood sugar levels stay steady. Other types of fibre speed up the passage of foods through the digestive system which helps alleviate constipation. Foods high in dietary fibre are even thought to reduce risk factors for some diseases, such as heart disease and cancer. The NHS advises us to eat 30g of fibre a day; beans, wholegrains, broccoli and leafy vegetables, nuts and dried fruit are all great sources of dietary fibre.
So, what can we conclude? That not all carbs are bad; wholegrains, fruits and other foods high in dietary fibre are great for our digestive health and are essential for a healthy body. But, not all carbs are good either; simple carbs such as white bread and white rice cause spikes in blood sugar which may contribute to weight gain and the development of Type II Diabetes.
Great, now we’ve got that cleared up, what about eating carbohydrates at particular times of the day? Some foods contain an amino acid called ‘tryptophan’ which contributes to feelings of sleepiness. Carbohydrates make tryptophan more available to the brain; this is then converted into the hormone ‘melatonin’ which helps us sleep. Therefore, eating a carbohydrate based snack before bed may help us get to sleep. Proteins from food are the building blocks of tryptophan, so a great bedtime snack is something that contains both protein and carbohydrates (such as wholegrain cereal with milk or peanut butter on wholemeal toast).
Okay, no, actually, bagels are the best kind of carbs
Carbohydrates are also very important in the restoration of energy stores after exercise. Many athletes focus on a protein-based post-workout snack. However, research has shown that eating 0.3-0.6 grams of carbohydrate for each pound of body weight within two hours of endurance exercise is essential for recovering lost energy stores. Protein does have other important uses after exercise, and provides the amino acids necessary to rebuild muscle tissue that is damaged during an intense, prolonged workout. The recommended ‘carbohydrate to protein ratio’ for optimal exercise recovery is 4g of carbohydrate for every 1g of protein. Eating more protein than that has been shown to have a negative impact on the body because it slows down the rehydration process and the restoration of energy stores.
Carbohydrates are also super important sources of energy before and during exercise. Complex carbohydrates provide the energy that fuels muscle contractions. Once eaten, they are broken down into smaller sugars (glucose, fructose, and galactose) that get absorbed and used as energy. I cannot stress this enough: CARBOHYDRATES PROVIDE THE ENERGY WE NEED TO MOVE.
Avocado on Sourdough: the afternoon snack of dreams
Eating enough carbohydrate also helps prevent protein from being used as energy. If the body is deficient in carbohydrate, protein is broken down to make glucose for energy. Because the primary role of protein is for building muscles, bone, skin, hair, and other tissues, relying on protein for energy and not eating enough carbohydrates can limit the ability of the body to build and maintain muscle and other tissues.
Moral of the story? Eat the right kind of carbs (wholemeal bread and pasta, brown rice, nuts and fruits) and eat enough of them. At least 55% of our daily calorie intake should come from carbohydrates (and more on days when we are doing exercise, especially if this exercise is endurance-based). The ‘diet industry’ has made carbohydrates the enemy and it’s so important that we overcome this mind-set and realise that carbs are our friend!