A person pours olive oil onto a salad.
Olive oil is the top choice among the mostly monounsaturated fats, which also include canola and peanut oils, avocados and walnuts. (For Spectrum Health Beat)

Even when you’re trying to lose weight, you need some fat in your diet for good health. While fat in general has gotten a bad rap, some types of fat—particularly plant-based fats—are good for you in moderation.

Good-for-you fats:

  • Olive, flaxseed oil and other plant-based oils.
  • Fatty fish.
  • Avocados.
  • Walnuts, other nuts and their oils.
  • Sunflower seeds and other seeds.


Our Take

Jessica Corwin, a registered dietitian at Spectrum Health Healthier Communities.

Jessica Corwin, a registered dietitian at Spectrum Health Healthier Communities reminds us that people have been eating less fat in the past 30 years, yet obesity rates have continued to rise.

What you should know: Not all fats are created equal and you actually need some fat in your diet to stay healthy.

“Certain fats are good in moderation,” Corwin said. “For example, the Mediterranean diet is one of the healthier ways of living even though it contains up to 35 percent fat with oils from avocados, olives and other foods.”

Mono and polyunsaturated fats are beneficial because they are a major source of energy, they tame down inflammation and they even help create healthy skin and hair. You also need fat in your diet to absorb vitamins A, K, D and E. Corwin discourages her clients from using fat-free salad dressings. Without the fat, your body can’t absorb nutrients from the vegetables in your salad.

Plus, fat-free food is less satisfying.

“You’ll feel more satisfied eating one ‘real’ cookie or a very small piece of cake than devouring a whole sleeve of fat-free snacks,” Corwin noted.

Based on their chemical composition, plant-based fats are either monounsaturated or polyunsaturated, though many have a combination. Both types have health benefits. Olive oil is the top choice among the mostly monounsaturated fats, which also include canola and peanut oils, avocados, walnuts, and many other nuts and seeds. Flaxseed in particular is exceptionally rich in ALA, or alpha-linolenic acid, one of the omega-3 fatty acids. Grind the seeds before you eat them or use flaxseed oil to get the most nutrients.

Plant foods high in polyunsaturated fats include soybean and sunflower oils, and some nuts and seeds. But one of the healthiest sources of polyunsaturated fats are fatty fish because they contain the other important omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The best fatty fish are salmon, tuna, trout, mackerel, sardines and herring.

The fats to limit are saturated fat, found mostly in animal foods such as red meat, full-fat dairy, butter and lard.

The fats to completely avoid are trans fats, which are oils that undergo a process that extends their shelf life, but makes them extremely unhealthy. Manufacturers are in the process of removing them from foods, but check labels because the deadline to fully comply with this U.S. Food and Drug Administration ruling has been extended to 2020.

Fats do help you feel more satisfied, but they’re also the most calorie-dense foods, so watch quantities, even when choosing the best sources.