Whatever you do in life, nutrition is important. But for sportspeople and tennis players, in particular, be it professional, semi-professional, or amateur, it can help give you a vital edge if you put in the right “fuel”. Here we look at some of the foods people should avoid or cut down on in the pursuit of tennis glory and trophies.

We begin with probably one of the more famous examples in recent years, at least from the tennis world anyway, and a certain Serbian, yes, it’s Novak Djokovic. Djokovic used to suffer from regular mid-match collapses, but as he revealed in his book, Serve To Win: The 14-Day Gluten-free Plan for Physical and Mental Excellence, a change in his diet proved pivotal.

The book was published a few years ago now — back in 2013 — and, as the title suggests, Djokovic revealed how he eliminated gluten, dairy, and sugar, all to a great effect. Indeed, since adopting his “new’” diet in 2010, he has gone on to become one of the best tennis players ever, and to date, he has won twelve grand slams — all but one since that decision to stop eating foods containing wheat, barley, rye, and oats.

Now, this is not to suggest that everyone should do this, and as Djokovic himself says in his book, every individual is different and needs to tailor their own diet.

“Most diet programmes assume the same plan works for everyone and that you ‘must’ eat certain foods. ‘Must’ just isn’t a good word. Your body is an entirely different machine from mine. I don’t want you to eat the best diet for my body. I’m going to show you how to find the best diet for your own unique self,” he wrote.

So where do you start?

If you are going to make a massive change to your diet like Djokovic, it is always recommended that you consult an expert first — ideally a dietician or a nutritionist, but make sure you know the difference between the two. Most will probably advise you not to eliminate anything entirely unless you have a diagnosed condition that warrants it. But if you do want to make some changes, just think carefully about what you eat and drink.

So, cut down on alcohol, soda, and caffeine, limit carbs and sports drinks, avoid “bad” fats (saturated) — replace with good fats like nuts and avocados — and also reduce your intake of processed foods (sausages, bacon, etc.).

Instead, try eating more vegetables, fish, and lean meats, and if you want an alternative to wheat and rice, try quinoa. If you find yourself wanting an odd alcoholic drink or a pizza, don’t feel bad about it, as long as it is the exception rather than the rule.

If you follow some of these tips it could very set you up for success in tennis and life in general. And maybe one day, you will be one of the players gearing up for Wimbledon or next month’s U.S. Open in New York, where Stan Wawrinka and Angelique Kerber will be hoping to defend their 2016 Grand Slam victories among the list of favorites, which will, of course, also include a certain Djokovic.