Why is the world of fitness still caught up in anecdotes and unfounded claims? Evidence-based approaches to losing fat or building muscle (body composition) are all but non-existent. Despite much research into diet and exercise, the fitness world is still largely guided by subjective opinion. Much of what is claimed is not based on research. Such claims and recommendations rarely consider individual preferences or lifestyles. Research reveals many insights. Metabolisms are not slow or fast. No diet is superior for weight loss when you consume the same amount of energy. Superfoods do not exist. Sugar is not inherently 'bad'. No food in itself causes weight gain or prevents weight loss. Detox diets don't work. You don't have to lift 'heavy' weights to build muscle. You don't need to exercise to lose weight. Fasted exercise does not result in greater fat loss. Most supplements have no evidence that they actually have any benefit. This book provides an evidence-based approach to fitness, covering how to diet and exercise to meet your fat loss or muscle gain goals in a manner that suits your needs and lifestyle. Contents: 1. Introduction 2. Should I alter my body composition? The exam analogy 3. Evidence-based practice 4. Research is research, right? 5. Body composition and health 6. The fuel for life 7. The hierarchy of nutrition 8. Diets 9. Advanced nutrition: protein intake for specific goals 10. Nutrient Timing 11. Manipulating the timing of energy intake: fasting 12. Food choice and dietary patterns for health 13. Alcohol 14. Non-sugar sweeteners and artificial sweeteners 15. Organic food 16. Evidence-based training for optimising body composition 17. Mechanisms of muscle growth 18. Principles of training 19. Training for muscle growth 20. Training splits 21. Exercise selection: variation 22. Timing: the time of the rest, the time of the rep and the time of the session 23. Advanced training techniques 24. Aerobic exercise 25. Supplements 26. Conclusion Sam Dicken is currently a Clinical Scientist at Guy's and St Thomas NHS Foundation Trust on the NHS Scientist Training Programme, specialising in vascular science. Sam has a degree from Cambridge University in Natural Sciences with a focus on physiology, development and neuroscience. He is studying for a Master's in Clinical Science at Newcastle University, and will begin a Medical Research Council Funded Master's in Research and PhD in experimental and personalised medicine at UCL in September 2020, with a focus on cardiovascular disease. He has experience of working in the sports nutrition industry, a wealth of clinical experience during his time in hospital, and a passion for sports and exercise, representing Cambridge University at varsity rugby and as a keen weightlifter with a focus on strength and body composition. Sam has a career focus on how diet, exercise and lifestyle influence metabolism, body composition and development of cardiovascular disease. He has fostered an interest in the continuum between health and disease, and how the very factors that may lead to disease and mortality are the same factors that allow individuals to become elite athletes or live long and healthy lives. This book combines his passion for physical training and exercise with his career skills, research interests and the evidence-based approach of his clinical training. This book will dispel common fitness myths and set the truth straight about how to eat and train to build muscle and lose fat.