We love reading diet books, almost as much as we love eating. High-fiber, low-fat, low-carb and sugar-busting diets abound. Though they’re not always based on solid science, we seem to learn valuable lessons from each passing craze. Case in point is the fat-free trend that took the country by storm (and almost didn’t go away).

There’s no doubt, fat is rich in calories. Gram for gram, fat has more than twice as many calories as carbohydrates and protein. And it’s true — some fats simply aren’t good for you. Trans fats are found in fried foods and processed foods (as well as in some meat products). They are unhealthy because they raise levels of unhealthy cholesterol (LDL) and decrease the level of healthy cholesterol (HDL) in our bodies.

Other fats cause problems too. Saturated fats are solid at room temperature. These include the skin on chicken or turkey and the visible fat on a steak. Saturated animal fat also contains cholesterol and promotes heart disease. We definitely need to limit the amount of saturated fat in our diet.

But some fats are good — our bodies require them. One of the unintended but positive consequences of the fat-free fatphobic madness is that we’ve finally learned the importance of good fat — in a balanced diet.

Fat provides a satisfying texture and mouthfeel. It also promotes satiety or fullness. Having a few nuts with a piece of fruit, or spreading a slice of avocado onto a sandwich (instead of mayonnaise) are delicious ways to help increase the feeling of fullness while delivering valuable health benefits. And if you’re watching your weight, good fats allow you to feel less deprived, too.

Omega 3s are an essential good fat (meaning our body doesn’t produce them — it’s essential that we get them from our diet). Every cell in our body uses omega 3s — they promote heart health and help improve brain function. They’re found in cold-water fish such as salmon and in plant foods such as flax seed.

Other perks of good fats include:

• They help increase our body’s absorption of fat-soluble vitamins such as Vitamins D, E, A and K and powerful antioxidants such as lycopene

• Lutein found in avocados is stored in the macula of the eye and helps promote eye health and decrease our risk for macular degeneration

• Vitamin E found in nuts, seeds, olives and avocados helps promote heart health

• Good fats help promote healthy hair and softer skin (and softer skin minimizes the appearance of fine lines!)

Yes, we need to remember that good fats are a concentrated source of calories and, as such, we need to limit them. But it’s important to make room for good fats in your diet, whether or not you’re trying to lose weight.

Here are suggested serving sizes and calories for some delicious, healthy fats:

Avocado: 3 slices/one ounce, 50 calories

Almonds: 10 raw almonds, 75 calories

Walnuts: 1 1/2 tablespoons (chopped), 70 calories

Lox or smoked salmon: 2 ounces, 75 calories

Cheryl Forberg RD is a professional chef and the nutritionist for NBC’s “The Biggest Loser.” She is the author of “Positively Ageless: A 28-Day Plan for a Younger, Slimmer, Sexier You.” For more information visit her Web site at www.cherylforberg.com.