INTRODUCTION The idea that nutrition and performance are inextricably linked is not new, but knowledge around the topic is growing and evolving all the time. The first scientific studies on carbohydrate and fat metabolism in athletes were conducted in Sweden in the 1930s, igniting an interest in diet as a performance aid. Since then, sports nutrition has become a standalone science, with many diverse branches and specialisms emerging over the years. While well-conducted scientific research is essential for understanding and advancing the field of sports nutrition, interpreting its findings isn''t always straightforward. Studies are often hard to access in full, inaccurately reported by the mass media, or they use a very specific group of parti-cipants, making them less relevant to the wider population. A study involving male trained athletes that looks at nutritional needs at altitude, for example, is not necessarily going to be relevant for untrained males, any female athletes, or those training at sea level. So where else can we go for information and advice on the best way to eat to fuel our training? Social media is a relatively recent phenomenon, and yet it is already hugely influential in shaping the lives - and food choices - of many. A study from Aston University in 2020 demonstrated that other people can have a huge influence over our food choices, concluding that: ''We may be influenced by our social peers more than we realize when choosing certain foods; we seem to be subconsciously accounting for how others behave when making our own food choices.

'' Indeed, we have to appreciate that nutrition in general, regardless of whether it is sports-related or not, is a highly personal and individual experience. Nutrition is multi-faceted, in that it is not just about the nutrients we put in our bodies, but also about the role it plays in our lifestyles, as well as the psychology involved. How we choose what we eat is influenced by many factors, which differ between people and also for any individual from one day to the next. They include: hunger and preference education budget, income and food availability cultural beliefs, family, peers and habits mood, stress and guilt media and social media food trends supermarkets/offers attitudes, beliefs and relationship with self. Additionally, we cannot forget that food choice is important because it creates consumer demand for suppliers who produce, process and distribute food.2 The global sports nutrition market was valued at 50.84 billion US dollars in 2018 and is expected to increase to 81.5 billion US dollars by 2023.

3 It is clear that big businesses have a lot to gain by using influential personalities to promote their products. While some sports nutrition products may have a part to play in optimal performance, most are just an expensive gimmick. If it sounds too good to be true, then it probably is too good to be true; in reality, there are never any quick fixes when it comes to nutrition, health or performance. We live in an age where anyone can set themselves up as an expert and reach millions without any relevant qualifications or experience and in a mostly unregulated space - sadly with potentially disastrous consequences for their followers. The rise and fall of the ''clean eating'' movement is a good example of widely accepted nutritional advice devoid of scientific or expert input. In the field of sports nutrition, the allure of fad diets also extends to their proposed performance benefits. Whether your aim is to get leaner, stronger or faster, to bulk up or drop weight fast, someone has a diet that guarantees success. There is no doubt that what we eat has a huge impact on both our physical and mental health and well-being, and on our performance when it comes to training for, and competing in, our chosen sport.

So how do we navigate the maze of conflicting information out there, choose a way of eating that is right for us, and make sure we do it as well as possible? That''s where this book can help. In the first part of this book, I aim to address each of the most popular athlete diets around today: what they are, how they work and how to approach them safely, with optimal health and performance in mind. I guide you through the key points you need to know, and the dangers and pitfalls to look out for as you go. In the second part, the focus is on population groups that are often overlooked in the sports nutrition world, where research is scant but the importance of good fuelling is still highly significant. For simplicity, I''m going to use the term ''athlete'' for all levels and abilities in sport. So, whether you''re a runner, cyclist or climber, recreational, professional or elite level, you''ll discover how to eat best for you and your sport based on both the most up-to-date science and my twenty years of experience as a dietitian and sports nutritionist.