Dietary carbohydrates are crucial for nutrition as they are the body's primary source of energy. The energy (glucose) from carbs provides energy to muscles.

The carbohydrates in our Indian diets come from a variety of cereals like rice, wheat, jowar, bajra etc. In a vegetarian diet, cereals are paired with pulses to ensure a complete protein. Cereals are deficient in protein (amino acids), and pulses contain incomplete protein. Pairing of the two complements and helps to create a healthy balance of a complete protein. While pulses are healthy, pairing them with carbs can be tricky. Most often, we pile our plates with huge amounts of white rice or we eat 3-4 chapathis with a small amount of dal and sabji. This results in the ratio of carb to protein being highly skewed, with a large percentage of carbs and far too little protein.

Why is this a problem? Ideally a nutritionally balanced meal should roughly contain 55-60 % of its calories from carbs (this includes whole grains, dietary fiber, vegetables and fruits). The remaining should contain 25% - 30% calories from protein and 10-15% calories from fat. However, it is commonly seen that diets contain 75%-80% of calories from unhealthy carbs (white rice, maida and refined sugars) and maybe just 10% - 15% calories from protein. When the energy from unhealthy carbohydrates is not being used, it gets stored as fat. This results in obesity and insulin sensitivity, which is so prevalent today. Protein on the other hand is used for building muscle and tissue repair by the body. The Indian Council of Medical Research (ICMR) recommends that energy needs should be assessed in terms of expenditure, rather than energy intake. This means eating according to how much you burn in daily activities and exercise. (1)

For those trying to lose weight or even for regular healthy eating, it is important to achieve a balance of nutrients. Initially while trying to lose weight, restricting carbohydrates can have a positive impact. This may lead to a quicker weight loss, than if one restricts only fats. Cutting calories and carbs may not be the only reason for the weight loss. You need to have a healthy balance of protein and heart healthy fats. People lose weight due to this extra protein and fat which keeps you feeling full longer.

Other health benefits:

Weight loss can help improve conditions like diabetes, high blood pressure, cardiovascular disease and metabolic syndrome. Cutting refined carbs and replacing them with healthy choices could be the reason for these positive changes. Choose quality lean protein like soy, legumes, fish, skinless poultry and low fat dairy. Include healthy fats (monounsaturated and polyunsaturated) like olive oil, flaxseeds, almonds, walnuts and fatty fish. Carbs which are eaten as part of the diet should consist of whole grains for additional fiber and nutrient benefits.

Reduced carbs can help suppress appetite

Dieting or restricting calories causes hunger, which is why most people do not follow restrictive diets for longer durations. Restricting carbs and replacing them with healthy protein and fats can lead to a reduced appetite. (2)

Research indicates that protein helps with satiety to a larger extent than carbs or fats. This helps reduce energy consumption. The body uses more energy to digest protein. Protein is the base of tissue and muscle formation. A good intake, helps retain/ build lean muscle mass while improving metabolism. (3) A healthy muscle mass boosts metabolism, making you burn calories effectively.

Abdominal weight loss

A reduced carb diet can also help target abdominal weight loss. Not all body fat is the same. Depending on where it is stored, it determines the risk of disease. This is especially important since fat stored around the abdomen is unhealthy. Excess accumulated abdominal fat leads to heart disease and type 2 diabetes. (4)

Lowering of triglycerides

Surprisingly a high level of triglycerides is caused by fructose (formed by the breakdown of carbs) and not fat. By cutting unhealthy sources of carbs, fructose levels reduce, causing reduction of triglycerides. On the other hand, when triglyceride levels reduce, this helps boost HDL (Good cholesterol). Eating the required amount of healthy fats as a replacement to unhealthy carbs can again help boost HDL levels. The Triglyceride: HDL ratio is a strong predictor of heart disease risk. A high ratio increases your risk of heart disease. By lowering triglycerides and raising HDL levels, a balanced-carb diet helps achieve a normal ratio. (5)

Type 2 diabetes

Carbohydrates are broken down into glucose, which enters the blood stream to be used for energy. Excess amounts which are not burnt for energy elevate blood sugar levels. The body responds with insulin which help bring glucose into cells for burning or storage (for later use). Those able to metabolise glucose properly have a quick response to insulin and are able to minimize the ‘spike'. However, in those with insulin resistance this is not the case, leading to Type 2 Diabetes. Cutting back on excess and refined carbs can help by bringing sugars to a healthy level and reducing the need for insulin to combat any sudden sugar surges. (6)

However, if you are on medication to treat diabetes, your treatment and diet protocol need to go hand in hand. Always work with your Diabetologist and Dietitian to lower sugar levels. Never attempt to self-medicate. The dosage of your medicines may need to be adjusted in order to prevent hypoglycaemia.

Are diets that highly restrict carbs healthy?

Restricting unhealthy carbs is very different form going low carb. Diets like the Atkins Diet or South Beach diet are not effective and healthy as they claim. While people may initially lose weight or feel healthy, once they re- introduce carbs back into the diet, they gain back the lost weight.

Low carb diets advocate removing every single source of carbohydrates, bringing down the intake to 8-10%. However, a balanced diet needs at least 55% of its calories from carbs. They are the body's primary source of energy. When carbs are severely restricted, the body responds by burning glycogen (muscle) for fuel. This may trigger initial weight loss, but leads to muscle wasting. To lose weight effectively you need to build muscle.

Eventually, when glycogen runs out as a source of fuel, the body starts to burn fat. This results in the formation of ketones which are by products of a process called ketogenesis. They produce a fruity odour in the breath.

Lack of energy can also cause one to feel hungry, dizzy and lightheaded. This affects the brain which thrives off of glucose to carry out its functions. The brain needs 130 g of glucose a day for optimal functioning. Going low carb also limits on the amount of B Vitamins available to the body. (6)

Cutting on carbs has led people to believe that any fat or protein is healthy. This is questionable, especially if the diet advocates unhealthy sources of fat like saturated fat and cholesterol. Low carb diets give the green signal to indulge in meats high in saturated fats, butter, lard etc. This increases levels of homocysteine, an amino acid that raises risk of heart disease. High levels of protein places an added burden on the kidneys and can lead to problems with bone health.

Points to focus on -
• Choose healthy whole grain carbs and stick to portion sizes.
• Resist the urge to load your plate with large amounts of white rice. Opt for brown rice instead which contains fiber, B vitamins and minerals.
• As an alternative to white rice you can also have dalia ( broken wheat), quinoa or millets
• Opt for whole wheat chapathis instead of puris or chapathis made from refined wheat flour (maida).
• Limit the portion sizes of rice and rotis so you can include healthy protein and vegetables
• Protein can be from vegetarian and non-vegetarian sources. Vegetarian sources include: dals, pulses, legumes and soy (which is a complete vegetarian protein). Non vegetarian sources include- eggs, lean meats, skinless chicken and fish. Meat should be cooked in a healthy way with minimal oil.
• Dairy- opt for skimmed dairy like milk, curd and buttermilk
• Healthy fats- fatty fish, walnuts, almonds, flaxseeds, avocado, cold pressed olive oil.
• Avoid too much sugar in your diet. This includes sugars added to tea, beverages, pastries and sweets
• Bakery products contain maida and unhealthy fats which need to be restricted
• Fruits contain sugars as well. For those trying to lose weight or those with diabetes, choose low calorie, non-starchy fruits. High calorie fruits need to be restricted to 1-2 portions once or twice a week.

References:
1. http://icmr.nic.in/final/RDA-2010
2. The effects of a low-carbohydrate ketogenic diet and a low-fat diet on mood, hunger, and other self-reported symptoms. McClernon FJ et al., Obesity (Silver Spring). 2007 Jan;15(1):182-7.
3. Protein, weight management, and satiety. D Paddon-Jones et al., Am J Clin Nutr May 2008 vol. 87 no. 5 1558S-1561S
4. Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women. JS Volek et al., Nutrition & Metabolism20041:13 DOI: 10.1186/1743-7075-1-13© Volek et al; licensee BioMed Central Ltd. 2004
5. Carbohydrate Restriction Alters Lipoprotein Metabolism by Modifying VLDL, LDL, and HDL Subfraction Distribution and Size in Overweight Men. R J. Wood et al., J. Nutr. February 2006 vol. 136 no. 2 384-389
6. http://care.diabetesjournals.org/