Frequently Asked Questions


– General

– Possible Side Effects

– Medical

– Allergies and Intolerances



1. How much water do I need to drink?

It is very important to keep hydrated while using Cambridge Weight Plan and this is why we recommend drinking at least 2.25 litres or four pints of fluid per day. This helps to maintain blood volume and to prevent dehydration. You should also remember to spread your fluid intake throughout the day and avoid consuming a large amount at once.

2. Why must I drink so much?

There are several reasons. A good rule of thumb for good health is to drink 2-3 litres of fluid a day whether trying to lose weight or not. If the Cambridge Weight Plan is used as the sole source of nutrition, this is the minimum for good health. The reasons for this include:

A Very Low Calorie Diet (VLCD) like Cambridge produces a natural water loss and this must be replaced.

Food is largely composed of water, just like our bodies. On the Sole Source Step, it is necessary to compensate for the fluid that would otherwise have been taken in through food. It is important to keep the body’s fluid levels topped up to prevent the unpleasant symptoms of dehydration – headache, dizziness, fatigue, irritability and constipation.

Cambridge Weight Plan offers balanced nutrition but in a very concentrated form, therefore if you are using Cambridge ready -made shakes or bars, we recommend that you drink 250ml of water with each product.

Extra fluid enables the body to get rid of the waste products associated with the breakdown of fats resulting from weight loss.

3. Is alcohol allowed while following Cambridge Weight Plan?

No. Alcohol is very high in calories (7kcal/gram) and has no other significant nutritional value. Alcohol is not medically recommended while following a reduced calorie diet.

4. Will I need vitamin supplements while using CWP?

The big plus about Cambridge is that unlike other weight loss programmes you do not need to take extra supplements. Each item offers a third of the recommended daily allowance of all vitamins, minerals and trace elements, so three a day gives the required amount of these.

The main worry when people go on food-based diets is that reduction in food means reduced nutrient intake, which in turn can put health at risk. It is impossible to achieve complete nutritional support from conventional food on less than 1000 kcal a day. Even then, extensive nutritional knowledge and a wide variety of foods need to be consumed to ensure adequate intake of all those vitamins and minerals.

Cambridge Weight Plan has solved that problem by formulating a diet that has programmes (up to 1500 kcal per day) using the diet as a nutritional foundation with conventional food. Cambridge Weight Plan customers have confidence that they can lose weight safely and not put their health at risk.

5. Do you recommend exercise with CWP?

Cambridge Weight Plan encourages all the well-known principles of healthy eating and a physically active lifestyle. Being physically active forms an important part of your weight loss journey, and is also key to your long-term weight management.

How much exercise you undertake depends on a number of factors: what Step you are following, any medical conditions you have or medications you take, your current capability for exercise, age, lifestyle and your current level of activity.

It is recommended that other than gentle walking, no physical activity be undertaken in the first two weeks of Step 1. This will allow your body to adjust to being on a VLCD. After this period, gentle to moderate intensity exercise is encouraged. If you want to do rigorous exercise at the gym or you are in training for a sports event, Step 3: 1000 kcal/day or more would be more suitable.

6. Do CWP products contain enough protein when taken as a sole source of nutrition?
The research undertaken to develop Cambridge Weight Plan showed that protein and carbohydrate provided by the diet were sufficient to protect lean body tissue losses.

Possible Side Effects

1. Why do I get a headache when on Cambridge Weight Plan?

Occasionally, during the initial few days, a person may experience carbohydrate or caffeine withdrawal and may develop a headache.

This is a temporary side effect and should be tolerated where possible. You may find a simple painkiller such as paracetamol may help. Insufficient fluid intake could also cause mild dehydration and an ensuing headache. Ensure that you are drinking the recommended amount of water.

2. Is it normal to get constipated after starting CWP?

Constipation is a common symptom of using a very low-calorie diet or low-calorie diet. The reason for this is the change in food eaten. Cambridge Weight Plan products contain the correct amount of dietary fibre but there is still less bulk entering the body, and straining may be necessary to excrete waste. It may be advisable to use a natural bulking agent such as Cambridge Fibre from day one of the diet programme as a preventative measure.

Psyllium husks, also known as Isphagula, have also been found to be particularly effective in preventing constipation. However if constipation persists for more than three days, or if you are suffering from physical discomfort, you should stop taking Cambridge Fibre or psyllium and seek advice from your GP or pharmacist about a suitable laxative.

3. I sometimes feel thirsty. Is this normal?

It is normal to experience thirst on occasions when dieting. The solution is simple; drink more liquids. We recommend that users of any Cambridge programme drink 2.25 litres [about four pints] of water each day. There is probably very little benefit to be gained from consuming more than double our recommendation of water intake.

4. Whenever I start Cambridge I feel nauseous. Is this normal?

Some people are more sensitive to the high concentration of minerals and vitamins in the products. Often a full glass of water before or following a Cambridge sachet or bar may eliminate nausea by diluting the effects of the minerals.

Another option would be to have your Cambridge sachets as 6/8 half portions, which would split the mineral content you have each time.

5. I notice a tendency towards bad breath. Why is this?
A mild ketosis may develop when on the Cambridge Weight Plan Sole Source programme and this may affect your breath slightly. Simply brush your teeth more often and use mouthwash or breath fresheners.


1. Can people with high blood pressure use Cambridge Weight Plan for weight loss?

Yes. If you have high blood pressure you may be able to follow any programme, depending on other health issues and your current BMI.

The Cambridge Weight Plan taken as a sole source of nutrition will itself cause water loss. The programme is low in sodium and results in a natural water loss in the early stages. This, along with your weight loss, will invariably reduce blood pressure in some cases.

Many people with high blood pressure have experienced blood pressure reductions after weight loss. Not only has there been a significant drop in blood pressure, but sometimes a decrease in medication has been required.

This is why regular monitoring is required while on the Plan. Hypertension medication and diuretics prescribed for hypertension will need to be monitored and adjusted throughout the weight loss period.

2. Can a person who has raised cholesterol levels use CWP?

Yes you would be able to do Cambridge Weight Plan. Studies have shown that using the Cambridge Weight Plan products as the sole source of nutrition may reduce levels of blood cholesterol by as much as 25% and blood fats (triglycerides) by 40% or more – the reduction seems to be greatest in those with initially high levels.

When patients returned to a normal diet the levels rose again but still stayed lower than baseline. There is also some evidence that following weight loss, ongoing use of the Plan as part of a healthy diet, i.e. with lots of fresh fruit and vegetables, cereals, lean meat, oily fish (e.g. salmon, herring, mackerel, etc.) and unsaturated fats may help control cholesterol levels. Please note that if you take medication for your cholesterol you will need to be monitored by your doctor, and as you lose weight this medication may need to be adjusted.

3. Is CWP suitable for people with coeliac disease?

We have a range of gluten-free products suitable for individuals with coeliac disease. Please visit the Allergies/Intolerances/Choices page or contact your Cambridge Consultant for further information.

4. Can someone with diabetes use CWP?

Customers who have type 1 and type 2 diabetes can follow Cambridge Programmes with the support of their doctor and/or specialist nurse.

If you take more than metformin medication for type 2 diabetes, you would have to start on Step 5: 1500kcal/day and work down the Steps every two weeks to the lowest suitable Step, which would be Step 2: 810kcal/day.

If you have type 1 diabetes, the process is the same as type 2, but the lowest programme you could step down to would be Step 3: 1000kcal/day.

We want you to have a slightly slower reduction in calories to ensure that blood glucose levels remain as stable as possible. If you have diet-controlled diabetes or are only prescribed metformin medication for your diabetes, you may be able to go on Sole Source (Step 1) and would not have to start on a higher programme; this is because you are not at risk of a hypoglycaemic attack (low blood glucose).

5. I suffer from gout. Can I still use CWP?

Gout sufferers generally have raised blood levels of uric acid (hyperuricaemia), which can cause crystals of sodium urate to be deposited in the joints – an extremely painful condition.

Using Cambridge Weight Plan as a sole source of nutrition may also raise uric acid levels. Anyone with a history of gout should be warned of this possibility. For this reason Step 2: 810kcal/day would be the most suitable programme for you if you are currently suffering from gout or you have suffered from this condition in the past.

6. What is ketosis and is it harmful?

When fat is released from fatty (adipose) tissue, it travels to the liver where it can be used to make more fat or be “burned” to produce energy. This energy production pathway produces ketones. Everyone has some ketones in their blood at all times but usually at low levels. The levels rise when fasting or while on a low carbohydrate diet designed to induce ketosis. Ketosis is a term applied to a state where the ketone blood levels are high enough to allow ketones to leave the body in the breath or in urine. Physiological ketosis is a normal protective mechanism reflecting the way in which the body switches its metabolism to “burning fat”. The effect of high levels of ketones varies from person to person. Some people feel euphoric, others may not feel hungry. There is little evidence that physiological ketosis is harmful.

7. Can someone with lactose intolerance use CWP?

Lactose intolerance is the inability to digest lactose (milk sugar) and is caused by a deficiency of lactase, an enzyme released by the small intestine that allows milk sugar to be absorbed into the bloodstream. Cambridge Weight Plan has a skimmed milk base and is therefore not suitable for those with this condition. However a range of Cambridge Weight Plan sachets made with soy milk is available. These are suitable for those who are lactose intolerant or who have a milk allergy. Please see the Allergies/Intolerances/Choices section for further information.

8. Is CWP suitable for anyone with a peanut allergy?

The Cambridge Peanut Crunch bar does contain peanuts. All the other products in the Cambridge range are not made in a nut-free environment and therefore may contain nuts due to the possibility of cross contamination. The only exceptions to this are the Cambridge ready-made shakes.

Please see the Allergies/Intolerances/Choices section for further information.

9. Why are pregnant or breastfeeding women advised not to use CWP?

Any woman who is pregnant, breastfeeding or who has given birth in the last three months cannot commence any Cambridge Weight Plan programme. Pregnant and lactating women require increased levels of protein and energy, and are advised to follow a diet rich in lean protein, whole grains, fresh fruit and vegetables.

In pregnancy, care has to be taken not to exceed intakes of some micro-nutrients, especially vitamin A, and all Cambridge Weight Plan products contain vitamin A.

Pregnant women cannot use any products as part of a programme or as a nutritional supplement. If you are trying for a baby then you would be able to use Cambridge Weight Plan but we would advise Step 2: 810kcal/day or above so that your diet includes some food. As soon as you become pregnant you would need to stop the Plan straight away.

10. Can I safely use CWP with a thyroid complaint?

With your doctor’s support, you would be able to follow all Cambridge Weight Plan programmes. We recommend that you should not use our lactose-free products where the main ingredient is soy because there may be a small effect of soy on levothyroxine.

Regular thyroid function tests are recommended as your medication may need to be adjusted as you lose weight.

For medical inquiries not mentioned above, please contact us at