Low carbohydrate diets have been gaining popularity over the years for those aiming for weight loss and now this diet is even being tried by people with diabetes in ways of managing glucose levels. However, both health practitioners and people diagnosed with diabetes are also confused about this dietary approach.

Weight loss users mostly adopt this dietary approach as they understand the strategy that results in a consistently lower intake of energy relative to the energy used. This method of weight loss involving lower energy intake for weight loss may be effective initially, but evidence to prove its effectiveness, in the long run, is limited.

So what is a low carbohydrate diet?

A low carbs diet is defined simply, as a diet that restricts the number of carbohydrates, you eat. Carbohydrates are grouped as simple and natural, that is found in milk as lactose and as fructose in fruits, simply refined table sugar that is used in processed food and drinks. The complex natural carbs that are found in grains and beans and complex as simple as in white flour.

In general, the complex carbohydrates are digested more slowly and therefore have a lesser effect on blood sugar when compared to refined carbohydrates as they contain fibre.

A common source of naturally occurring carbohydrates that are complex include:

Grains. fruits, vegetables, Nuts, seeds and legumes.

Our body uses carbohydrates as a source of energy and breaks it down to simple sugars during digestion, and makes it readily available in the blood as energy for the cells by insulin. Extra glucose is stored in the liver and muscles, converting some to fat. A low carbs diet is intended for the body to burn the stored fat to enable weight loss.

Typical food for low carb diet

A low carbs diet will typically focus on proteins and non-starchy vegetables. A typical low carbs diet will exclude grains, legumes, fruits, bread, sweets, pasta and starchy vegetables and some will exclude nuts and seeds. Some low-carb diets may allow small amounts of fruits, vegetables and grains. A daily allowance of 20 to 57 grams of carbs that provides 80 to 240 calories, is also known as a very low carbohydrate diet. Again some low carbs diets may restrict carbs in the initial stage and then slowly increase the number of allowed carbs.

The dietary guidelines recommend an allowance of 45% to 65% of your daily energy intake should be from carbohydrates.

Does a low carbohydrate diet work?

Evidence shows that there is weight loss of about 1 to 3 kg with a low carbohydrate diet is successful on a low carbohydrate diet within the first few days due to the depletion of glycogen (stored carbohydrate) and is also associated with water stores too. However, in the medium and long term, this diet is not as effective in faster weight loss or better maintenance of weight loss, as traditional energy-restricted diets.

Pros and Cons of low carbs diets

Most of the research concludes that while evidence shows that a low carbohydrate diet may show improvement in both the glycaemic index and weight loss, only for the short term and not significantly better than a higher carbohydrate diet on a long term basis. Again a low carbohydrate diet is not sustainable in a long term and attention has to be paid to the dietary recommendations.

Similar benefits in losing weight and managing blood sugar have also been achieved through diet patterns like the Vegetarian diet and Mediterranean diet which can be high in carbohydrates. While there is evidence to show that with a low carbohydrate diet, lower HbA1C and weight loss can be achieved, most studies are uncontrolled. Researchers also noted that there is impairment in cognitive function with low carbohydrate diets.

Other concerns cited with low carbohydrate diets with Type 1 Diabetes also include micronutrient deficiencies, growth restriction in children, development of ketoacidosis, hypoglycemia and dyslipidemia.

A word of caution

A sudden reduction in carbs can cause temporary side effects like headache, constipation and muscle cramps, nausea, poor concentration and halitosis (bad breath), particularly in the initial stages, as a process called ketosis sets in, using fat as the primary source of fuel because of insufficient carbs.

Some health experts believe that increased consumption of fat and protein from animal sources may lead to increased risks of cardiovascular diseases and cancer.

A moderate approach

A low carbohydrate diet is only one of the many dietary approaches to control weight loss and management of blood sugar for type 2 Diabetes in a short term. However, they are not the only option and may not be the best dietary approach for optimal health. Those who would like to adopt a low carbs diet should be encouraged to choose more plant sources of protein and fat over animal sources and include dietary fibre in their diet by choosing from high-fibre plant foods, nuts and seeds and low carbohydrate fruits. Moderation is the key to optimal health and with lifestyle changes, your goal of weight loss can be achieved.