Sports Nutrition: Is eating junk food and drinking soft drinks really bad for an athlete’s performance?


By Ms.Fia RND -Sports Nutritionist/Elite Fitness Coach

Q: Is eating junkfood or drinking softdrinks during or before a competition really bad for an athlete’s performance?”

First, let’s talk about “Junk food”.

When it comes to Nutrition and Food, there’s no such thing as “Junk Food”. We actually call it empty caloric food, because these food contains high amount of Calories. Calories from either Carbohydrates (simple sugar) or Fat. And we all know that as an athlete, we need calories to fuel our body, esp on cramming days.

Let’s say, you’re a triathlete who trains 5/6days a week. You have a fast metabolism rate and an active lifestyle. You need 3500-4000calories per day to meet your daily energy expenditure. And for glycogen-dependent events/training, you need to refuel and refill muscle glycogen the fastest way. A slice of all cheese -vegetable pizza (400-500calories/slice) or a bowl of Tomato spaghetti (400-450calories/serving) can be beneficial.

When we talk about nutrition during or before intense trainings/events, we are talking mostly about Carbohydrates. Yes, with protein and fat. But it’s all about carbohydrates. We need easy to digest type of carbs (with a little fiber and fat, to slow down digestion), and these High Carb -empty caloric food, like milkshakes-vegetable pizza-chocolate bar-ice cream, is a must have. But be reminded that only 5-10% of simple sugar is the allowed daily allowance in our diet. That means, a male/female athlete can at least enjoy 1 cup of iced tea or 1 small tub of ice cream per day (with proper timing).

Surely, eating the healthy way is important to get all the nutrients, vitamins and minerals our body needs. But for athletes, eating that much calorie is also a good idea.

Is JUNK FOOD really bad?

Not at all. It depends on “how” junk it can be. (still, I recommend to avoid foods high in saturated fat / Cholesterol)

But, it doesn’t mean you will just have junk food in your diet all the time.

MAJORITY of your diet should always come from nutrient-dense food like fruits, vegetables, dairy products, lean meat and whole grains.

These so-called junk food should also have a space in your diet.

If you’re trying to optimize your performance (during high intensity training/competition) and your health as an athlete, these convenient high –empty caloric food is better than your bowl of salad.

Q: Is drinking soft drinks/soda during or before a competition really bad for an athlete’s performance?

Yes, if taken in excess.

Soft drinks/Carbonated drinks may cause GI distress.

The following symptoms can affect and slow down  performance:


-lower blood sugar

Bloating is one of the common effect of having excessive carbonated drinks, like soda, in an athlete’s diet if consumed quickly or in a large amount. Carbonation builds up gas in your stomach resulting to a more difficult feeling that can affect efficiency and slows down performance. And if taken in an empty stomach or someone that has stomach ulcer, it may also again, affect and delay performance.

On the other hand, if consumed quickly or in a large amount, these high-sugar drinks may cause elevated blood sugar and then in the long run, it may drop down drastically making you feel weak and tired (hypoglycemia). I recommend to take non-carbonated sports drink that has 25-30g sugar per 250ml -for a 1hr training. And consume only 50-70ml every 15mins. 

Always balance your diet. Proper nutrient timing is also the key to optimize nutrition in your diet.


-Ms.Fia Batua RND

Registered Nutritionist Dietitian

Sports and Medical Nutritionist – Elite Fitness Coach

©Copy rights reserved 2016

Email me at


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