Carbohydrates are essentially sugar; they are broken down from their original form (glucose, sucrose, maltose etc.) into sugar which insulin converts into energy. When we eat too much sugar, our bodies store the excess in muscle tissue and in our liver, and when those reserves become 'full', the sugar is transported and stored in fat tissue. Hence sugar makes us fat. So when you read about a new miracle diet that claims you can lose several pounds, sometimes half a stone, in a week, think about the carbohydrate (sugar) content of that diet.
When a diet is high in carbohydrates - and I mean really high - it will cause weight gain due to the excess sugars being stored as fat. If we eat a moderate, healthy amount of complex carbohydrates (wholegrain, whole wheat and wholemeal foods) we will not gain weight; our bodies will utilise the energy and release sugars steadily over several hours. However sugars found in refined or processed foods such as white bread, white pasta and white rice - not to mention cakes, chocolates and biscuits - are broken down so rapidly that our body becomes overwhelmed and builds up the at reserves.
Most, if not all, 'diets' have one thing in common: a dangerously low level of carbohydrates. Take the Atkins, for example, which advocates eating high-fat, high-protein foods and completely abstaining from carbohydrates. Weight loss is rapid yet you are being duped into cutting out an absolutely essential food group. When too much glucose (sugar) enters the body, it is stored as glycogen (that's what is stored in muscles, the liver and eventually as fat). Glycogen is a water soluble molecule that is easily mobilised when the body requires a sudden surge of
energy. When it is required by the body
for energy, it is converted back into glucose.
When the body perceives danger
in the form of a famine or a period of starvation (i.e. a low-carb diet - because carbohydrate-rich foods are often also sources of B vitamins, iron, zinc, magnesium and fibre), a process known as
glycogenolysis takes place in which the enzyme glucagon is secreted to convert
glycogen back into glucose which is then used for energy. Initially, during a
crash diet, glycogen is mobilised from some fat reserves, however the rapid
weight loss often talked about in reference to ‘miracle diets’ in which people
claim to lose half a stone or several kilograms in one week, is not actually just
excess fat being lost, but rather it is mainly fluid and muscle tissue. This
fluid contains glycogen, thus depleting the body’s essential energy stores. Each glycogen molecule is linked to four times its weight in water, so when these stores are used for energy, the body weight which is lost is simply water and muscle tissue, not just fat.
When your body notices that its energy stores are becoming depleted, it panics and tried to replace it, thus storing any subsequently consumed carbohydrates - no matter how complex and healthy - as fat. This is why you may notice a sudden weight drop on a low-carb diet such as the Atkins, fasting, intermittent fasting, a detox and most other fad diets, followed by a plateau. During the plateau your body is retaining every carbohydrate molecule it can from fruit, vegetables, grains, pulses or whichever food is 'allowed'.
On a crash diet, when the body perceives starvation, the
basal metabolic rate (BMR) – or metabolism – slows down as a survival mechanism,
meaning it desperately tries to preserve stored fat. While the fat is being
protected and preserved there is only one energy store available for the body
to use: glycogen. When the glycogen stores are utilised and the body then
becomes deprived of glycogen, the autonomic nervous system is triggered and you will experience extreme and constant hunger which is, once again, a
survival mechanism. At this stage, most of us would assume we'd 'fallen off the wagon', 'given in' or 'lost our willpower' but what's actually happened is our bodies are fighting for survival. A lack of glycogen, and therefore a reduced BMR, will
result in tiredness, depression and irritability which are all commonly
experienced by people on restrictive diets and ultimately by those who constantly subject themselves to yo-yo dieting. This is because the body is
functioning below its optimum rate as a way to preserve energy, and all of the
body’s systems are affected.
High Protein Diets
Both low protein and high protein diets are dangerous, and
one danger of a high protein diet is calcium loss in the body. Too much protein
in the diet causes calcium to be excreted in urine and this happens more when
animal protein (i.e. meat and dairy) is consumed. This is due to amino acids (the building blocks of
protein) being released during the digestion of protein which results in the
blood becoming acidic.
As the body attempts to counteract acidity, calcium
is extracted from the bones and eventually excreted in the urine. The reason
animal protein causes this more prominently is due to its amino acids being
high in sulphur, and high sulphur-containing amino acids are particularly prone
to extracting calcium from the bones. As more calcium is lost, the risk of
developing osteoporosis (weak, brittle bones) increases.
If you want to lose weight there is simply one way to do it:
- Calculate your BMR to find out how many calories you need each day. Try the official Diabetes Uk BMR calculator here
- Create a meal plan, basing each meal on the NHS Eatwell Plate - an excellent guide to how much of each food group your body needs
- Eat every three to four hours - only when you are hungry, and stop when you are full
- Do not starve. Do not restrict calories. Do not cut out any food group. Do not fear fat.
- Consult a nutritionist, dietician or weight consultant for advice (I am currently offering completely free email, skype and phone consultations - contact me at Rosie_Nutrition@Outlook.com - no strings attached)
- You never need to restrict your calorie intake to below 2000 calories (women) or 2500 calories (men) - if you are overweight, you are eating more than this, and a few simple tweaks can help you reduce your calories to meet your body's requirements and therefore bring you back to your healthy weight
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