Very Low Calorie Diets (VLCD’s)

 By Mizpah Matus B.Hlth.Sc(Hons)

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.


  • 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
 By Mizpah Matus B.Hlth.Sc(Hons)
Last Reviewed: December 19, 2014. Disclaimer


  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. SS

    Oh yea, I take a Centrum Forte, Caltrate, Vit E, 1000mg of Omega 3 daily!

  7. SS

    I have been on this for 3 weeks and lost a total of 13 pounds. I am on 900-1000 cal a day. Weekdays: 1 protein bar a day, 3 protein shakes a day with 2% = 160 cal each, 100g of lean protein, 1 fruit a day, 3 vegetables a day. No butter or oils, just herbs and seasonings. Weekends I add 1 slice of whole wheat toast, and cut out 2 of the shakes and the bar and add in another 100g lean protein with another vegetable. But I seem to be at a pleateau or stand still. I work out 5x a week, medium intensity, Wii Active, about 25 minutes a day. SO FUN! I am now 5’1″, 184 pounds. I did a body fat test online with various body meaasurements they asked for and I got a 27%. Can anyone help me? I am also hypoglycemic so I have to eat every couple hours, but this weight loss has helped that alot! 36 years old!

  8. jackie flynn

    I have been doin the lighter life diet which is similiar to the canbridge and done under medical supervision. You also go for counselling. i have tried every diet you can think of and this is the only one i can work with. its not for everyone but its definetely the one for me. People try to scare monger without reading the actual facts. this diet is done with monthly medical checks. i have lost 8 stone and will shortly be going on to the management programme. i would definetely recommend this programme.

  9. tracy mculloch

    sounds great but need set menu or food becomes an issue.ive tried all classes for weight loss but just cant count points etc ad am 5 stone over weight thanks HELP

  10. chels

    you should never eat less then 1200 calories a day. EVER. losing weight takes time and and very hard work. you need to eat 5-6 healthy meals a day and exercise at minimum 3 times a week. cutting your calories to 500 a day will OF COURSE make you lose weight. so will not eating at all. its not just about how you look its also what your doing to the inside of your body. being over weight destroys your organs and health. so does starving yourself. 500 calories is not healthy for anyone. you need to talk to a doctor so he can slap some sense into you.

  11. ME

    i have been off my diet for awhile now. but…i have watched what i ate and watched my portions. i have gained maybe 1 pound in 2 weeks(which is due to my occasional desserts i’ve been craving like hell) but i’d like to say if you’re going to go on this diet make sure you get medical supervision or take good vitamins i noticed after about 2 months into the diet i started bruising REALLLY easily everywhere(mostly on my legs) i can’t think thats healthy:/but good luck to everyone-it is a success if you stick with it.

  12. tanya

    i lost about 25 pounds in 2 months when i ate less than 800 calories a day. it was hell. i maintained this weight for about 1.5 yrs, but gained it all back. im now at my highest weight 🙁 and looking to lose it again..a healthier way so i dont feel so deprived

  13. Janealane

    In response to Hanna’s post on may 6th. I would suggest that you switch the timing that you eat. In stead eating your big meal later eat a bigger breakfast and then the snacks for lunch and dinner. This will help your metabolism speed up during the day and you will burn more. Also, drinking something like V8 is a great way to get your veggies and it is low cal. A great breakfast that I love is the Fage greek yogurt with strawberries. It has a good amount of protein and tastes great. Another tip is that if you work out in the evening try to eat some protein afterward (I like a hard boiled egg) and then do not eat anything till the next day. Your metabolism will be burning those stinky cals all night. I am currently 139 and would like to be in the 115-120 range. If anyone has any tips let me know! Thanks and good luck to everyone!!

  14. ME

    So I’ve been on this diet since april 3rd. I am 124 pounds right now. I have went so terribly off this diet this weekend due to 3 family partys with lots of junk food! but no worries i am goin back on my diet tomorrow, i gained 2 pounds due to my 3 day slip! but it’s summer for me, and I plan to excercise a lot more now! some advice for people-if you go off track during the day don’t give it up the rest of the day and eat even crapier-everyone makes mistakes, but you can always recover from your slips. don’t give up. I went from a size 13 to a size 7 pants. it’s great to be able to fit into jeans without problems.

  15. Tina

    I have been following the bettermd plan for 8 weeks and have lost 32 pounds, I highly recommend it! It is great to have someone to do this with! I walk almost everyday for 1 hour, but that is the extent of my exercising. I buy my food from bariatric choice. You can search either name to get the web address. Also, try miracle noodles….no cals or fat. They are different, but they are good.