My patient had brain fog and fatigue despite blood sugar medication, diet and exercise routines: What did he overlook?

The zero-carb diet may not be the answer for people living with diabetes

Undoubtedly diet and exercise are very important in those overweight or obese in achieving weight loss goals and reducing blood sugar levels.

Prashant, one of my patients, was very meticulous about his lifestyle discipline once he was diagnosed with diabetes. He changed his diet, exercised regularly, rewired his body clock to sleep a full eight hours. So, I was surprised the day he walked in, looking very lethargic and worn out. “Doctor, I am taking my medication on time and maintaining my food and exercise routines. But over the last few weeks, I have been feeling shaky, weak and have brain fog. I feel like resting all the time. Why is this happening?,” he asked.

So, I went over his routine once again. He told me that he had a low-calorie diet and had cut carbohydrates to nil in each of his meals. Simultaneously, he had also pushed his exercise routines to an extra 20 minutes every day. The problem was staring at me right there. One of the common mistakes most patients make after being diagnosed is under-nourishing themselves with a severely calorie-restricted diet, which does more harm than good. He had fallen into this trap of over exercising and under-nourishing his body.

Undoubtedly diet and exercise are very important in those overweight or obese in achieving weight loss goals and reducing blood sugar levels. But the truth is a zero-carb diet is not the answer and may be counter-productive. You may restrict calories but you need complex carbs, which do not break down so easily in the body, in your basket. A diet must have a portion of macronutrients, be it carbs, proteins and fats.

Why a zero-carb diet may wear you out

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Zero-carb diets can harm people with diabetes, especially those on insulin, by plunging their levels of blood sugar suddenly, what we call hypoglycemia. They can lead to nutrient deficiencies due to the exclusion of many fruits, vegetables and wholegrains, which are rich sources of vitamins, minerals and fibres, too. Such diets lead to electrolyte imbalance and dehydration. This happens because in the absence of carbohydrates to draw calories from, the body uses up stored glycogen, which usually releases water.

But the worst is ketoacidosis, when the blood becomes toxic. Deprived of carbohydrates, the body burns fat for energy instead of glucose, breaking fat to organic compounds called ketones. This process is called ketosis. But when the body produces too many ketones, they make the blood acidic.

Overdoing diet restrictions result in undernutrition and frank malnutrition, a term for severe malnutrition that manifests in the patient’s physical symptoms. Such patients lack physical strength and become frail, losing lean muscle mass.

What should you watch out for?

If you are on a calorie-restricted diet, make sure it has adequate protein along with minerals and vitamins. If not, this can lead to undernutrition. Second, back up the diet with muscle strengthening exercises. Do resistance training at least twice or thrice a week to work all muscles in the upper and lower parts of your body and prevent frailty. If you are undernourished, fatigue manifests easily, interrupting usual functionality of the body. As far as the brain is concerned, without proper nutrition, you will get brain fog.

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A balanced low-carb diet can still include nutrient-dense, high-fibre carbohydrate sources like leafy vegetables, nuts and seeds, rather than a completely zero-carb approach. Diet is particularly important in the time of weight loss pills, which reduce lean muscle mass drastically. Unless we take sufficient calories, protein and do not drink enough water, we could develop the same symptoms my patient did.

(Dr Mohan is Chairman, Diabetes Specialities Centre, Chennai)