Ask the Experts - Nutrition

Answers from Andrew Hamilton:

Q. I’m 5ft 5ins and weigh just under 10 stones. I’ve recently taken up running and try to eat healthily. While I’ve lost a bit of weight already (6lbs in 2 months), I am thinking of going on a low carbohydrate, high protein diet to accelerate fat loss, in order to improve my 10K run time. Can you advise me the best way to go about this and how long should I follow this diet? I would appreciate any advice you can give me.

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Answer:

Your BMI (weight in kilos divided by height in metres squared) is around 23.5, which although not in the ‘overweight category’ is probably a bit high for optimum running performance. However your current rate of weight loss of around 3/4lb per week is actually ideal; a gentle rate of weight loss indicates that you’re shedding mainly body fat and not vital muscle tissue. You don’t mention your frame size, but I would suggest that around 9 stones would be a good initial target for a recreational runner (a BMI of just over 20). At your current rate of weight loss, this would take about 4 months to achieve, which in the scheme of things is not such a long time! I would strongly urge you not to go on a low carbohydrate diet for a number of reasons:

• Carbohydrate is the prime source of fuel for activities such as running; you will struggle to maintain a training routine if you consume a low-carbohydrate diet. Since aerobic exercise like running is also an excellent way of stimulating fat burning, a low carbohydrate diet could actually end up hindering your fat loss efforts;

• Low carbohydrate diets are known to reduce immunity in those who are physically active, leaving you open to illness and infection;

• Low carbohydrate diets often leave you feeling tired, irritable and susceptible to food cravings, resulting in poorer food choices and lower overall quality of diet;

• Restricting your carbohydrate intake while training often leads to muscle tissue loss. Weaker muscles can increase your risk of injury.

Given that you’re already on the right road to weight loss and the fact that your running fitness will be gradually increasing anyway as you progress with your training, I think you should stick to your current eating patterns and not embark on a diet – low carbohydrate or otherwise!