What's more important, the foods you do eat or the foods you don't? When you add or subtract something from your diet, it's important to consider the other side of the equation in order to remain nutritionally balanced.
• One of the lessons from the low-fat era was that advice to limit saturated fat wasn't helpful without recommendations about what to eat instead. Replacing saturated fat with refined carbohydrates isn't good for cardiovascular and metabolic health, while swapping it for polyunsaturated fat does improve health. Public attention has swung from fat to sugar but it's also important to focus on things like getting enough vegetables and protein.
• It's generally a good idea to focus on including more of the foods we benefit from, rather than simply on the foods we "shouldn't eat," because it helps ensure that we get the full spectrum of nutrients needed for good health. When you add a new food without subtracting something else, you could increase your overall calorie intake beyond what your body needs.
One benefit of correcting the low-fat dogma is that healthy polyunsaturated and monounsaturated fats are back on the table. Nuts, seeds and avocados are full of heart-healthy fats, fibre, and a host of nutrients, but they also have a lot of calories.