Dietitian, Annica Rust, educates us on why following fad diets during or after cancer treatment is not a good idea.
Obesity has significantly increased over the last 50 years. It occurs when your energy intake is more than the energy you burn. One of the major dangers of obesity is that it increases your risk of developing cancer and the risk of cancer reoccurrence.
What are fad diets?
Various fad diets have been adopted in an approach to lose weight. A fad diet can be defined as a restrictive weight loss plan that guarantees quick weight loss. It’s also characterised by limited food options or unusual food combinations without scientific evidence1,2,3.
Fad diets do not come without consequences. Well-known fad diets are the Atkins, Ketogenic, Banting, The Eat Right for Your Blood Type (ERFYBT), Juicing, and The Human Chorionic Gonadotropin (HCG) diet.
Most fad diets are very low in energy to promote quick weight loss. Losing weight too fast results in muscle and water loss and not necessarily fat loss. The rapid weight loss can also cause constipation, weakness and fatigue3,4,5.
Diets that are very low in energy can also lead to gout, gallstones (from higher serum cholesterol), cold intolerance, light-headedness, nervousness, anaemia, menstrual irregularity and non-alcoholic fatty liver disease4,6.
Nausea, headaches, dehydration, and inadequate vitamin and mineral intake may also occur as the result of following a fad diet3.
Two popular fad diets pertaining to cancer is the Ketogenic diet and Juicing. Let’s take a closer look at them.
The Ketogenic diet
This is a low carbohydrate, high fat diet with adequate protein. A low-carbohydrate intake is the primary requirement for ketosis.
Ketosis refers to a physiological shift whereby the body makes use of fatty acids and ketones (the by-product that is formed from fat breakdown) to produce energy instead of using glucose.
It is thus thought to believe that the Ketogenic diet will ‘starve’ cancer cells from using glucose for energy. However, there is insufficient evidence that the Ketogenic diet will eradicate cancer and that it will improve the outcomes of cancer patients.
More studies are needed before the Ketogenic diet can be recommended as a treatment regime for cancer patients. Furthermore, your kidneys will have to work harder to filter the ketones which can cause kidney damage3,7,8.
Other side effects include, dehydration, fatigue, kidney stones, low sugar levels, gastrointestinal distress, high cholesterol and a decreased bone density3,8,9.
The risk for a cancer patient outweighs the potential benefit of following a Ketogenic diet.
Juicing is defined as the process of extracting the juice from the pulp of vegetables and fruits.
It can be an easy way to add a variety of fruit and vegetables to an already adequate diet, which includes five servings of fruits and vegetables.
However, relying only on juices to meet your nutritional requirements while undergoing or recovering from cancer treatment is not recommended. It results in a reduction of fibre intake, and can lead to weight gain due to increased energy intake.
If you are unable to chew or struggle with swallowing and digestion, juicing may be part of a meal plan to make it easier to reach your nutritional requirements.
What is the solution?
Fad diets are never a healthy choice when receiving cancer therapy or for cancer survivorship. Cancer and cancer therapy can put your body under a lot of stress, and following a fad diet only puts it under more stress.
The aim is not to focus on losing weight whilst receiving cancer therapy, but rather to maintain a healthy weight. If weight loss is deemed necessary, it will become a focus point for cancer survivorship.
Fad diets are thus impractical and unsustainable as they have strict regimes that are monotonous and do not promote lifestyle change.
A well-balanced diet, small and realistic lifestyle adjustments and physical activity remain the golden standards to lose weight successfully5. Contact a registered dietitian for detailed guidelines on cancer prevention, treatment, survivorship and palliation.
MEET OUR EXPERT – Annica Rust
Annica Rust is a registered dietitian practicing at the Breast Care Unit in Netcare Milpark Hospital as well as in Bryanston. She assists with medical nutritional therapy for cancer prevention, treatment, survivorship and palliation. She gives individualised nutritional care to prevent or reverse nutrient deficiencies, nutrition-related side effects and malnutrition to maximise quality of life.
- Porter, S. Food Fact sheet: Fad diets. The British Dietetic Association.2017; 1(1):1.
- Jauregui-lobera. Fad diets, miracle diets, diet cult… but no results. Journal of negative & Positives Results. 2017; 2(3):90-93.
- Khawandanah, J & Tewfik, I. Fad Diets: Lifestyle Promises and Health Challenges. Journal of Food Research. 2016; (6):80-89.
- Lysen, K. L & Israel, D. A. Nutrition in weight management. Mahan, L.K., Escott-Stump, S. & Raymond, J.L. (eds). Krause’s food and the nutrition care process. 13th ed. St Louis. MO: Elsevier Saunders: 2012.
- Crowe, T. 2008. Nutrition Messages Given By Fad Diets Can Alter People’s Food Perceptions. Nutridate. 2009; 19(2):1-4.
- Dajani , A & AbuHammour, A. Treatment of Nonalcoholic Fatty Liver Disease: Where do we Stand? An Overview. Saudi Journal of Gastroenterology. 2016; 22(2):91-101.
- Daniels, J. Fad diets: Slim on good nutrition. Nursing. 2004; 34(12):22-23.
- Saltzman, E., Thomason, P. & Robertse, S.B. Fad Diets: A Review for the Primary Care Provider. Nutrition in Clinical Care. 2001; 4(5):235-242.
9] Rogovik, A. L. & Goldman, R. D. Ketogenic diet for treatment of epilepsy. Canadian Family Physician. 2010; 56(1):540-542.