Extra calories obtained from the food intake are deposited as fat in the body. As the name says, low carb diet plans limit the carb intake. Easy to digest carbs are restricted and food with higher quantity of protein and fat is incorporated in the diet.
Generally term ‘low carb diet’ is used for ketogenic diets. Ketogenic diets are the ones, which contain carbs in limited amounts so as to enhance ketosis. Usually these diets are followed by obese people for weight loss. But these may be used for problems like diabetes, epilepsy etc.
Low carb diets have been followed since years when obese people stopped taking sugar, potatoes, bread, butter etc for weight loss.
In 1967, ‘Stillman’s diet’ became popular which mainly advocated low carb, low fat and high protein diet. This was followed by Dr. Atkin’s diet (1972), which had its share of criticism, too. But it was widely followed by all who wished to loose weight.
It is claimed that around 2000, almost 18% of US population was following a low carb diet. It was generally recommended that less starch and more protein and fiber should be included in the diet.
Low carb diet plans are mostly based on Atkin’s diet. Although there are many other popular ones like Zone diet, South beach diet etc. these follow the same ground rules as Atkin’s.
Low carb diets are diets where carb intake is reduced to a level that almost stops insulin production in body. This enhances ketosis or ketone production to be used as energy instead of glucose
In these diets, points like carb metabolism and its absorption in the blood affecting the blood sugar level, are taken into account. The levels of sugar in blood are maintained by two man hormones, which are produced in pancreas.
- Insulin: helps in lowering blood sugar.
- Glucagon: increases sugar levels in blood/
When food intake is high in easily digestible simple carbs, it increases insulin secretion and excess calories are stored as fat in the body. Low carb diets inhibit insulin secretion and encourage ketosis. This reduces body fat.
In low carb diet plans, nutritive carbs are suggested to be kept at low levels. So potatoes, bread, deserts, rice and sweets should be avoided. Some diet expert suggest only 20 – 30 gms of nutritive carbs everyday, whereas some advice to take 225 – 325 gms of nutritive carbs. So amount of carbs, types of food allowed in low carb diet differ from diet to diet.
One point is universally accepted that processed sugar and refined flour products should be taken as less as possible. Similarly the amount of fat intake advised, also vary from diet to diet, but a moderate amount of fat is recommended.
Arguments between insulin synthesis and ketosis:
Carbs are easy t metabolize and increase glucose levels in blood. Body cells use this glucose as energy for their function. Excess blood sugar is harmful for the body. So the pancreas secretes insulin so that liver can transform the blood sugar into glycogen and triglycerides (fat). So high carb diet results in an increase in insulin.
When low carb diet is taken, levels of blood sugar fall down and body cells do not get enough glucose for energy. In such case, pancreas secretes glucagon. This breaks down stored glycogen to glucose. When stored glycogen is used up, this enzyme stimulates liver, which produces ketones from the stored fat by ketosis. So low carbs diets result in less amount of insulin secretion.
Of these two processes, which one is beneficial and which one is harmful to the body, is the point being still argued upon.
However, scientific studies show that low carb diet plans are effective for short periods and not beyond six months. Reports about long-term effects of this diet plan are still not fully known.
The positive effects of low carbs:
The effect of low carb diet on a group of women showed somewhat less risk of heart disease than the group of women on high carb-low fat diet. It has been found helpful in diabetes and cancer patients, too. In another study, a low carb (0 gms carb in 200 cal. Diet) diet was tried for 10days and results showed that subjects reduced more body fat than control group, which was on complete fast. Yet another study showed low carb diet reduced weight as well as blood pressure and cholesterol.
Low carb diet removes fluid retention and so there is considerable weight loss initially. Later it is gradual weight loss as excess fat is removed. Some researches claim that reduction in carbs brings on fatigue. It is also felt that these diets lack essential nutrients and vitamins. Some low carb diets consist of less amount of fiber, causing constipation.
Processed food (especially sugar & refined flour products), potatoes, rice, corn etc should be avoided. Fruits, vegetables, seafood, poultry etc are included. But still higher quantities should be avoided. Unprocessed, nutrient rich foods should be incorporated.
Different diet plans like Atkin’s, Protein power, South beach, zone etc. advocate different ingredients. But basically same principle is followed --- carbs should be cut short, replaced with protein and/or fat. Various recipes are available in book form and also on internet to choose from, to suit individual requirement