If you’re planning to cut down on your fat intake, remember to keep on eating the “good” fats.

When it comes to dietary fat, what matters most is the type of fat you eat. Contrary to decades of dietary advice, newer research shows that some fats are not only beneficial for health; they are, in fact, necessary.

Perhaps surprisingly, one of the most recommended and evidence-based diets for overall health—the Mediterranean diet—hasn’t been associated with weight gain, although it contains relatively high amounts of fat. This is because the fats are mostly unsaturated fats, some of which are robustly associated with extended lifespan, including a sizeable reduction in the risk of severe respiratory disease.

Of special importance in fighting immunity-related issues and supporting healing are a group of unsaturated fats known as polyunsaturated fatty acids (PUFAs): omega-3s and omega-6s. These fatty acids are vital for building healthy cells and they have anti-inflammatory and antioxidant properties that improve resistance to many diseases.

For instance, a study carried out by using Nightingale Health’s technology showed that a 12-week diet loaded with omega-rich fish, among other healthy foods, improved the underlying biomarkers of Fatty Acid Balance and Dietary Fatty Acids, two of the key contributors to your Immune Age.

Omega-3 and omega-6 are essential fats to incorporate into your diet, because your body can’t produce them on its own. So, rather than adopting a low-fat diet, focus on eating foods rich in omegas and other unsaturated fats.

These include plant oils (such as extra virgin olive oil and expeller-pressed canola oil, but not coconut and palm oil), nuts (especially walnuts), seeds (chia, hemp, and flaxseed), and oily fish (mackerel, salmon, and herring).