The Diet Compass summary

Most diets, whether low-fat or low-carb, are based on the same simple premise: Maximize your protein intake while minimizing your intake of everything else. And, generally speaking, it’s not a bad rule. For starters, protein is essential to life, since it provides the material that our cells are made from. High-protein foods are also more filling than low-protein fare; the more protein you eat, the fuller you’ll feel. As a result, you’ll eat less and lose weight.

But, as with most things in life, a healthy diet depends on a healthy balance. And protein, like just about everything else you’re likely to eat, can lead to disease if consumed to excess.

There’s an Ancient Egyptian proverb that holds up well in our modern times: "A quarter of what you eat keeps you alive. The other three quarters keep your doctor alive.” But nowadays we have information to help us change this ratio and require fewer trips to the doctor. What’s key is finding out your metabolic type and how well your body processes carbohydrates.

Most people have normal insulin sensitivity and so can digest carbohydrates without any problems. Insulin-resistant people, on the other hand, hardly break down any sugar. Their body converts carbohydrates directly into a spare tire. That's why many insulin-resistant people are overweight.

By now you know a bit about proteins and carbohydrates. So let's move on to the most maligned end of the nutrient chain – fats.

First things first: fats don’t necessarily become body fat. Some types of fat do cause weight gain, but others are very healthy and even important for building muscle. These different types of fat are divided into four categories that differ at the molecular level.

Let’s talk about drinks. What would you choose for a cozy Sunday morning, when you want something comforting but also healthy? Maybe a glass of orange juice, for that refreshing jolt of vitamin C? And a cup of coffee with milk, for that extra bit of calcium – but only one cup, because, as we all know, too much coffee is bad for the kidneys! Or is it?

When it comes to beverages, most people don't have a clue what's really healthy, and there are a lot of persistent myths. Juice, for example, is actually anything but healthy. Even though it contains vitamins, it’s simply teeming with dangerous sugar.

You’ve surely heard of the much-hyped trend of intermittent fasting. Some people swear by the 16:8 rule – fast for 16 hours, then eat whatever you want within an eight-hour window. That means you can eat cheesy eggs, buttered rolls, and fatty bacon for breakfast, but only very light foods like herbal tea and miso soup in the evening.

Robust evidence suggests that healthy eating involves not only the right foods but also the right timing of your meals. But what, precisely, does that mean?

Saturated fatty acids, trans fats, glycemic values, autophagy. Phew, that was a lot of biology and chemistry. Aren't there a few simple rules you can follow?

You bet! Here are 12 simple, actionable nutrition rules – no degree in biochemistry required.