Can crash dieting affect blood-cell production, and does it have implications for blood cancer? Oncologist explains

Dr Liza Bulsara warns against crash diets, as they can hinder blood cell production due to nutrient deficiencies, stressing the importance of a balanced diet.

Dieting is one of the most popular ways people try to lose weight. When combined with strength training, mindful eating with a calorie deficit has been shown to be beneficial for our bodies in a healthy way; however, when it is just about restricting what you eat while depriving you of essential nutrients, the habit can pose a problem.

In a conversation with HT Lifestyle, Dr Liza Bulsara, a haematologist and paediatric oncologist at MOC Cancer Care, Pune, explained the problem with crash diets and how they affect blood-cell production, and ultimately, whether they have implications for blood cancer.

Blood cell implications of extreme diets

According to Dr Liza, crash diets, which promise rapid weight loss, have become increasingly popular, particularly through social media. “Extremely low-calorie diets, prolonged fasting, and restrictive eating plans may produce quick changes on the weighing scale, but they can also leave the body short of nutrients needed for normal blood-cell production,” she explained.

Restricting yourself of nutrients will only harm your body.

Iron deficiency, for example, Dr Liza stressed, can eventually lead to iron-deficiency anaemia, resulting in:

1. fatigue
2. weakness
3. reduced oxygen-carrying capacity of the blood

Similarly, deficiencies of vitamin B12 or folate can interfere with the normal formation of blood cells and cause specific forms of anaemia.

Dr Liza further pointed out that crash dieting becomes especially concerning when weight loss comes at the cost of nutritional adequacy. “A person may lose weight, but if the diet is severely restricting protein, iron, vitamin B12 or folate, the bone marrow may not have the building blocks it needs to produce healthy blood cells,” Dr Liza added.

The Indian diet is to be blamed too

However, Dr Liza noted that persistent fatigue or abnormal blood counts should not be attributed solely to dieting; they warrant a proper medical evaluation.

This is particularly relevant in the Indian context, according to her. She stated that dietary patterns in India vary considerably. “People following highly restrictive vegetarian diets, eliminating entire food groups or relying mainly on juices, salads, or meal replacements, may need to pay greater attention to nutritional adequacy,” she explained.

People following highly restrictive vegetarian diets need to pay greater attention to nutritional adequacy.

The ICMR-National Institute of Nutrition's Dietary Guidelines for Indians emphasise dietary variety and adequate intake of both macronutrients and micronutrients.

Does crash dieting cause blood cancer?

But there is an important misconception to address, according to Dr Liza: “Crash dieting does not cause blood cancer.”

“Leukaemias, lymphomas, and other blood cancers develop through complex genetic and biological changes. Nutritional deficiency can cause abnormal blood counts or anaemia, but this is fundamentally different from cancer,” Dr Liza stressed.

“The problem is that symptoms can sometimes overlap. Tiredness, weakness, frequent infections, or unusual bruising may occur for several reasons, including nutritional deficiencies and blood disorders. If such symptoms persist, a doctor may recommend a complete blood count and other tests rather than assuming that dieting is responsible,” she added.

Therefore, she stressed that a proper weight-control program requires gradual changes rather than starvation. It is much healthier for an individual to have a well-balanced Indian meal that includes sufficient protein, vegetables, fruits, and pulses, along with vitamins and minerals.

Lastly, Dr Liza stated, “Weight loss should improve health, not compromise the body's ability to maintain it.” And this is what many forget.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.