Doctor Ranj Singh has issued a serious warning to people trying to lose weight - especially as summer approaches. Highlighting just how dangerous this can be, the doctor took to the BBC Morning Live programme to discuss diets, especially crash diets.

Although they can help you 'lose weight fast', he noted that these diets work 'because they severely restrict calories and you lose a lot of fluid and water. But, and this is a big but, because they're so restrictive, they can lead to nutritional deficiencies because you're missing nutrients, vitamins and minerals."

Not only are diets also "very difficult to maintain," but Singh stressed that "eating should be fun and enjoyable, too." And some people may feel worse while dieting.

Fast diets can "put you at risk for long-term health problems like osteoporosis, anemia and gallstones. If you're already at higher risk for eating disorders, it's a really bad idea, and conversely, they can lower your metabolic rate, which is counterproductive to what you're trying to do."

As for protein, he notes that "protein-based diets are nothing new" and there's evidence that they work, as they can "reduce your hunger level, (lower) your blood sugar a little bit better, and they can increase your calorie burn because your body has to expend more energy to burn the protein. But they're not for everyone."

In this approach, only animal products are consumed, completely excluding foods of plant origin, resulting in a very low carbohydrate diet that also excludes fruits and vegetables.

Some of the potential benefits include weight loss, regulating appetite, which promotes a feeling of satiety, stabilising blood sugar, reducing inflammation and improving mental clarity, the doctor revealed. In fact, Singh said:

"There is evidence for low-carbohydrate diets in the treatment of type two diabetes. But there are some serious risks to consider. It is high in animal fat, which can lead to elevated and unregulated cholesterol levels."

"This diet is high in red and processed meat, which we know increases the risk of things like bowel cancer. You exclude vegetables and fruit - we know they're associated with reduced risk of heart disease, bowel cancer and things like that - and are really rich in fibre, which is good for you, and obviously we worry about deficiencies like vitamin C, E and folate, which is found in fruit," the expert added. 

"We don't know what the long-term risks of this kind of thing are," he warned, citing the story of a 40-year-old man who ate only butter, cheese and hamburgers. The man also cut out carbohydrates and after eight months began to develop "cholesterol deposits in the skin."

"The average man needs about 56g of protein a day and the average woman needs 45g a day," the doctor warned. In fact, as an example, just "one chicken breast already contains 30 g of protein, so it's pretty easy to make sure you're getting enough protein," Singh added. | BGNES