Very low calorie diets are regarded as extreme diets and anyone interested in trying the diet should consult their doctor or specialist who can assess its suitability for you.

• Very low calorie diets are defined as those with a calorie intake of 1,000 calories or less for 12 weeks and often rely on commercial meal-replacement products such as diet milkshakes, soups or bars.
• Very low calorie diets should only be followed under supervision, ideally from a registered dietitian, and may require medical monitoring.
• This can be achieved through carefully creating a weight loss plan with a support of your healthcare team

Is the diet safe to follow?

• Very low calorie diet plans should not be followed by children, or pregnant or breastfeeding mothers.
• You should always inform your Healthcare team at your GP practice if you are changing your diet plan. They can help you decide whether it is the right diet for you and whether you may need to adjust any regular medication.

British Dietetic Association verdict

• Rapid weight loss can be motivating, but it's unsustainable. People often regain weight after the diet and, overall, research suggests there's little difference between a Very Low Calorie Diet (VLCD) and conventional weight loss after 1 to 2 years.
• A VLCD requires regular support and counselling from a healthcare professional and is very effective with people who have struggled to lose weight for years.
• A VLCD that involves eating 1,000 calories or fewer should not be followed for more than 12 continuous weeks.
• One issue with very low calorie diets is ensuring you get enough essential vitamins. A dietitian can help you to ensure your nutritional needs are best met whilst following the diet.