NHS & NICE Compliant
VLCD Explained — Everything You Need to Know
A Very Low Calorie Diet (VLCD) is one of the most clinically effective methods for rapid, safe weight loss. Here's what it is, how it works, and whether it's right for you.
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Read the FAQs
Always consult your GP before starting a VLCD programme.
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100% daily vitamins & minerals
The basics
What is a Very Low Calorie Diet?
A VLCD is a structured, medically-recognised diet plan involving fewer than 800 calories per day — through nutritionally complete meal replacement products.
<800
Calories per day on a VLCD
12
Max consecutive weeks per NICE guidance
BMI 27+
Minimum BMI with GP approval
100%
Daily vitamins from 4 KeeDiet products
What does a VLCD involve?
On a VLCD, you replace some or all of your regular meals with specially formulated, nutritionally complete meal replacement products — providing essential vitamins, minerals and protein while significantly reducing your daily calorie intake.
How is it different from a regular diet?
Unlike conventional calorie-counting diets, a VLCD uses total or partial food replacement to create a significant calorie deficit. This triggers your body to burn stored fat for energy — a process known as ketosis — resulting in faster, more consistent weight loss.
Why use meal replacements on a VLCD?
It is very difficult to follow a VLCD safely using conventional food alone. Meal replacement products are specifically formulated to provide complete nutrition at very low calorie levels, making the process safe, simple and sustainable.
NHS & NICE guidance
What do the NHS and NICE say about VLCDs?
VLCDs are not a fad diet — they are a clinically recognised, medically endorsed weight loss method.
NHS
NHS & NICE Definition
The NHS and NICE guidance defines a VLCD as any plan providing fewer than 800 calories per day. NICE recommends VLCDs should only be followed for a maximum of 12 consecutive weeks, after which a structured TFR Break is required before continuing.
GP
Doctor's Approval & Support
Following a VLCD with your doctor's support is a safe and effective way to reduce body fat and lose weight quickly. KeeDiet recommends consulting your GP before starting — particularly if you are taking prescribed medication or have an existing medical condition.
Suitability
Is a VLCD right for you?
VLCDs are not suitable for everyone. Here's who can and can't follow a VLCD plan safely.
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BMI 30+ (standard recommendation)
VLCDs are generally targeted at those with a BMI of 30 or above who need to lose a significant amount of weight safely and quickly.
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BMI 27+ with GP approval
Your GP may approve a VLCD for those struggling to lose weight with a BMI of 27 or above, particularly if there are related health conditions such as Type 2 diabetes.
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Type 2 diabetes management
The NHS now recommends a VLCD 'soups and shakes' programme for eligible Type 2 diabetes patients as part of its Path to Remission programme.
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Not suitable for BMI under 27
Those with a BMI below 27 should not follow a VLCD without specific medical guidance.
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Not suitable during pregnancy or breastfeeding
VLCDs should not be followed during pregnancy or while breastfeeding under any circumstances.
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Not suitable for those under 18
VLCD plans are not appropriate for anyone under the age of 18.
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BMI 40+ — seek specific guidance first
Those with a BMI of 40 or above may be advised to start on a higher calorie plan initially. Your GP will advise on the most appropriate approach.
KeeDiet plans
KeeDiet's VLCD Plans
All KeeDiet VLCD plans follow NHS and NICE guidance, providing under 800 calories per day with 100% of your daily vitamins and minerals.
Our most popular VLCD plan. Four KeeDiet products per day providing under 800 calories. Low carb, ketogenic — designed for fast, consistent weight loss.
4 products/day
~750 calories
Ketogenic
BMI 30+
Based on the DiRECT trial and Newcastle Diet Study principles. Three KeeDiet products mixed with milk plus vegetables — the closest equivalent to the NHS soups and shakes programme.
3 products/day
~800 calories
Type 2 Diabetes
BMI 30+
The Man Plan is specifically designed for men with five products per day. The Social Plan offers flexibility for those who need to eat out occasionally whilst still following a structured VLCD.
4–5 products/day
~800 calories
Flexible
BMI 30+
Ready to start?
Not sure which VLCD plan is right for you?
KeeDiet has been helping people lose weight safely with VLCD meal replacement plans since 2008. Our UK-based customer support team can help you choose the right plan for your goals, BMI and lifestyle.
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Common questions
Frequently asked questions about VLCDs
Everything people commonly ask before starting a Very Low Calorie Diet.
What does VLCD stand for?
VLCD stands for Very Low Calorie Diet. It refers to any structured diet plan that provides fewer than 800 calories per day, typically using nutritionally complete meal replacement products such as shakes, soups, bars and meals.
How long can you follow a VLCD?
According to NHS and NICE guidance, a VLCD can be followed for a maximum of 12 consecutive weeks. After this you must take a structured TFR Break for at least one week before returning to your plan. You may also follow a shorter 4-week cycle, taking a break every 5th week.
Is a VLCD safe?
Yes — when followed correctly with your doctor's support, a VLCD is a safe and clinically effective method for rapid weight loss. KeeDiet's meal replacement products are nutritionally complete, providing 100% of your recommended daily intake of vitamins and minerals across four products per day.
Will I feel hungry on a VLCD?
During the first few days your body adapts to the reduced calorie intake. After this initial period, most people find that hunger reduces significantly as the body enters ketosis. KeeDiet's high-protein formulas also help keep you feeling fuller for longer.
Can I exercise on a VLCD?
No planned exercise is recommended during the first two weeks of a VLCD. From week three onwards, gentle exercise is encouraged. High-impact exercise should be avoided while on a very low calorie plan as your energy intake is significantly reduced.
Do I need vitamin supplements on a VLCD?
No — four KeeDiet meal replacement products per day provide 100% of your recommended daily intake of essential vitamins and minerals. A separate multivitamin supplement is not necessary when following a KeeDiet plan correctly.
Can a VLCD help reverse Type 2 diabetes?
Clinical evidence from the DiRECT trial showed that a VLCD using meal replacements helped over 50% of participants achieve remission from Type 2 diabetes within 12 months. The NHS now runs its own soups and shakes programme based on these findings. KeeDiet's Fast Fix plan follows the same principles.
Medical disclaimer: The information on this page is intended for educational purposes only and does not constitute medical advice. VLCDs are not suitable for everyone. Always consult your GP or a qualified healthcare professional before starting any very low calorie diet plan, particularly if you are taking prescribed medication or have an existing medical condition. KeeDiet recognises and endorses the safe practices laid down by the NHS and NICE Guidance on Obesity for Very Low Calorie Diets.
