In "Fit for Life: Not Fat for Life," Harvey Diamond presents a lifelong approach to eating that emphasizes balance and health without the need for strict diets or deprivation. Diamond advocates for a diet composed of 50% raw (living) food and no more than 50% cooked food to maintain optimal physical and mental health. He shares his personal journey of overcoming health issues through this nutritional program and provides practical advice on how to eat any food in the most healthful way. With a focus on fresh fruit juices, hearty salads, and avoiding dairy products, Diamond's method aims to make the eating experience enjoyable and sustainable.