Are weight-losing diets harmful to the functioning of kidneys?

These high protein and low carbohydrates diets such as the keto diet produce a very high quantity of nitrogenous wastes and acid load, forcing the kidney to work harder to eliminate them.

ByDr Sashi Kiran A

Published Mar 09, 2023 | 2:54 PM Updated Apr 18, 2023 | 4:23 PM

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Today, 9 March 2023, is World Kidney Day. Kidneys perform a variety of functions in the body.

Apart from excreting excess water and metabolic waste products, kidneys play a vital role in maintaining bone health and help in the production of haemoglobin.

Each kidney is a conglomeration of around a million nephrons.

These nephrons have a limited capacity to regenerate. Only the tubular cells of the nephron can regenerate following damage. The rest of the cells comprising the nephron cannot regenerate, hence damage to them can be permanent.

Kidney diseases are increasing in incidence and prevalence due to changes in our lifestyles. A sedentary lifestyle, and consumption of junk foods and alcoholic beverages providing empty calories cause metabolic syndrome.

This in turn causes diabetes mellitus and hypertension. which are the two main causes of kidney disease.

Keto diet is hard on our kidneys

Of particular concern in recent times are diets that are similar to the keto and Atkins diet (high fat with high protein and low carbohydrate diets). On World Kidney Day 2023, let us look at the effect of keto diet on kidneys.

Present-day youth, who are conscious about their physiques, resort to consumption of high protein, high fat, and low carbohydrate diets.

These diets such as the keto diet have the inherent risk of damaging our kidneys.

Also read: Study links keto diet to risk of heart disease and strokes; doctors agree

Hyperfiltration injury of kidneys due to keto diet

Our body is designed to use carbohydrates as an immediate source of fuel, fats as a storage form, and proteins as a source of fuel only as a last resort (starvation).

While it is easy for our body to produce energy from carbohydrates, it takes a lot of metabolic pathways to be activated to produce an equal amount of energy from fats and proteins.

In other words, fats and proteins are inherently inefficient sources of energy. This leads to weight loss when someone is consuming a diet with a disproportionately high content of fats and proteins — making these diets popular among youth who aim to lose weight and have a sculpted body.

These high protein and low carbohydrates diets such as the keto diet produce a very high quantity of nitrogenous wastes and acid load, forcing the kidney to work harder to eliminate them.

This results in hyperfiltration injury of the kidney. Over a period of time, this would lead to renal failure.

Also read: Is intermittent fasting good for weight loss?

World Kidney Day: How to take care of them?

Hence of paramount importance is to consume a diet that is balanced in nature. Such a diet is rich in fruits, vegetables, whole grain, low-fat dairy products, fish, poultry, beans and nuts. It should also be low in sodium, sugars, fats, and red meats.

It is also important to realise and remember that kidney diseases are notoriously asymptomatic.

Symptoms appear only after substantial damage has occurred to the kidney. This makes it imperative for us to suspect, evaluate and treat a kidney disease as early as possible.

Individuals who have risk factors for getting a kidney disease need to check their kidney function periodically even in the absence of any symptoms.

Also read: Paleo diet blamed for death of wife of Tamil actor Bharat Kalyan

(Dr Sashi Kiran A is consultant nephrologist, Yashoda Hospitals, Hyderabad. These are the personal views of the author)