Current diet trends such as LCHF; Banting; and the ketogenic diet all claim that dropping carbohydrates from your diet and focusing on fats and proteins is the best way to lose weight. The food which is most commonly associated carbohydrates is bread, followed by pasta and rice.
These diets are trying to flip the food pyramid and educate people on how macronutrients are broken down by the body and why fats should no longer be viewed as the enemy.
The main idea behind the diets is that eating fats will not make you fat, carbohydrates will. But how does bread lead to weight gain?
There are two types of carbohydrates: simple carbohydrates and complex carbohydrates. Most bread, such as white bread, bought from leading supermarkets are composed of simple carbohydrates. Simple carbohydrates are made up of fructose and glucose. Refined grains, like bread, are stripped of their fibre and the starchy endosperm is left behind, which is broken down and absorbed rapidly by the body to be used for energy.
Simple carbohydrates’ rapid absorption leads to a spike in blood sugar levels – this causes a negative chain reaction throughout the body. The high blood sugar levels cause the body to produce more insulin. Insulin is released by the pancreas and is responsible for telling the cells to absorb the blood sugar and store it as fat for energy in the future.
The stored fat does not end up being broken down when you eat a diet high in carbohydrates because the body uses the carbohydrates available before it switches to its reserves, which results in more fat being stored in the adipose tissue. The body only uses a small amount of glucose for liver function and muscle maintenance and the rest is stored away.
It is not possible to gain weight when your calorie input is less than your calorie output, regardless of what you are eating in a day; eating refined bread can cause you to eat more food throughout the day. The spike in blood sugar levels is matched by an equal drop in blood sugar levels.
A sudden drop in blood sugar levels results in an energy dip, sluggishness and loss of mental focus. The brain then signals to the body that it needs another fast absorbing carbohydrate in order to keep functioning, which results in a person grabbing the next pick-me-up treat.
This constant yo-yo energy leads to more food being consumed in a day, a high calorie intake and weight gain. Other dangers linked to a diet consisting of simple carbohydrates, also known as High-Glycaemic (High GI) foods, are: type 2 diabetes; heart disease; cancer; infertility in women; and muscle degeneration.
This does not mean that you have to cut bread out of your diet completely. There are many types of bread which have not been stripped of their fibre and nutrients, such as Low GI bread; rye bread; and sourdough bread, which take the body longer to break down and keeps you feeling fuller for longer.
The key to maintaining a healthy weight is to ensure the blood sugar levels do not spike in either direction but remain at a balanced level throughout the day.