EAT THIS & YOULL GET FAT . I am keeping this a simple and short as possible . Eat "Good or Bad" foods in large amounts you will gain fat...why? Because your eating in a surplus (more than what you need). . It does not matter whether its avocado, nuts, crisps, chocolate you can still gain weight. . One meal will not make you fat the same way 1 salad wont make you skinny. Get a good understanding of the content in food, track it using myfitness pal. This will tell you calories, carbohydrate, protein and fat in food and its a free app you dont need to pay for premium, you will learn so much about food when you track it.