Very Low Calorie Diets (VLCD’s)

very-low-calorie-dietsA Very Low Calorie Diet (VLCD) is a diet where normal meals are replaced with drinks, soups, or bars.

The typical daily calorie intake is on or under the 800 Calorie mark – however the aim is to be as nutritionally balanced as possible.

These diets are popular because initially people can lose a lot of weight quickly.

However, if a VLCD isn’t done correctly it can have negative consequences on a dieter’s health.

Prescription Only

A VLCD is normally only used privately and in the medical profession to bring about rapid weight loss in the dangerously overweight person.


These diets should be undertaken only under medical supervision. They are typically a high fat, high protein diet that will bring about Ketosis.

This is when the body breaks down fat for energy instead of using glucose.

Used for Short Periods Only

The diet is only undertaken for a short period of time (a few weeks). In some situations, the meal replacements may only be used for two meals a day – therefore bringing about slower but more manageable weight loss.

Safe VLCD Diets

Medifast This has been used by (apparently) over 1 million people, and is endorsed by John Hopkins University. It’s a meal replacement plan around the 800-1000 calories mark (which puts it outside the strict definition of a VLCD). It will put the body into a mild state of ketosis.
The Cambridge Diet Used in the UK, this diet has an even lower daily calorie level (400-600) and is a high protein, low fat, low carb diet.
Bernstein Diet For some patients an 800 calorie meal plan will be perscribed.
Newcastle Diet Medically supervised VCLD that reverses type 2 diabetes.

Dangerous Very Low Calorie Diets

HCG Diet This 500 Calorie diet can be dangerous if not supervised by an approved clinic.
Sacred Heart Diet Nutritionally deficient and very low in calories.
Cabbage Soup Diet This soup based diet lacks nutrition and is very low in calories.
3 Day Diet This VLCD can be dangerous if done more than 3 days.


Generally exercise isn’t recommended while a person is on a VLCD as the calories consumed aren’t sufficient to support it.

However, some plans recommend light exercise such as walking or swimming for those with an excessive amount of weight to lose.


Initially people following very low calorie diets can lose a lot of weight, which keeps these diets popular.

However, they can be dangerous long-term because they often lack the nutrition your body needs and can actually crash a person’s metabolism.

If a dieter wants to use a VLCD, he or she should only do so under medical supervision and if extreme weight loss is needed.


A very low calorie diet is not recommended unless under the care or a physician or medical team and is intended for those that have a considerable amount of weight to lose.

It isn’t for those who only have 10-20 pounds to lose and can be especially dangerous for those dieters.

 By Mizpah Matus B.Hlth.Sc(Hons)
  • González-Pérez, J., Sánchez-Leenheer, S., Delgado, A. R., González-Vargas, L., Díaz-Zamudio, M., Montejo, G., … & Herrera, M. F. (2013). Clinical Impact of a 6-Week Preoperative Very Low Calorie Diet on Body Weight and Liver Size in Morbidly Obese Patients. Obesity surgery, 23(10), 1624-1631. link
  • Johansson, K., Sundström, J., Marcus, C., Hemmingsson, E., & Neovius, M. (2013). Risk of symptomatic gallstones and cholecystectomy after a very-low-calorie diet or low-calorie diet in a commercial weight loss program: 1-year matched cohort study. International Journal of Obesity, 38(2), 279-284. link
  • Moreno, B., Bellido, D., Sajoux, I., Goday, A., Saavedra, D., Crujeiras, A. B., & Casanueva, F. F. (2014). Comparison of a very low-calorie-ketogenic diet with a standard low-calorie diet in the treatment of obesity. Endocrine, 1-13. link

57 Comments or Reviews

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  1. Elizabeth

    I Need a very simple diet for one, I work 2 jobs and I don’t need to cook up a storm, I found this website and it is great because it caters for the single person, being very busy. Is there any other simple diets that you guys could put me onto.

  2. nancy

    I have non diabetic hypoglycemia and desperately need a low calorie diet that will meet my needs as far as food is concerned. I hope someone can help me. thank you nancy

  3. instantlock

    PLEASE PAY ATTENTION : Even if you are under professional supervision, make sure you are taking necessary amounts of nutritions (vitamins, minerals, aminoacids and lipids). Only counting calories can ruin your health. You MUST have this free open source software CRON-O-METER , believe me, it ROCKS, nothing like it. If your VLCD does not achieve recommended amounts for all (never does-1200cal. is minimum for that) you will need some multi vitamins. Over the counter one-a-day, centrum are not good (fake), google it if you want to know really good ones.

  4. Shannon

    Update: I have one year of maintaining my weight. I started VLCD low carb on Sep 18, 08. Lost 60lbs by Mar 09. Last June I was at 140. Today (May 2010) I weight 145. I’ve inspired two people to consider VLCD. One, female, joined the same weight loss center I joined which is supervised by a nurse. I was surprised that one, male, is doing the same diet at a local hospital.

  5. penny hammonds

    hi,i have lost alot of weight but now i think i am stuck.with the start of the new year i want to lose some more.the vlcd sounds great to me.can you give some tips.i look so forward to doing this.

  6. sandy

    The 800 vlcd is working for me. Losing 2.5 lbs a week while maintaining a proper high fiber (more than 20g) and high protein diet, and exercising 3 days a week (strength training mostly to get that sculpted athletic look). I feel energized throughout the day. Stay away from sugar, eat plenty of veggies and in order to keep fiber in your system, buy some Metamucil Clear & Natural..keeps you from craving foods and controls your blood sugar levels.

Last Reviewed: April 6, 2017