Salter says, "It's important to make unsaturated fats the focus. Examples include nuts, seeds, nut butters, avocado, fatty fish (salmon, tuna, mackerel), egg yolks, olive and canola oil. Unsaturated fats have a positive impact on heart health, blood lipid levels, and possess anti-inflammatory properties."
Say yes to a salmon dinner with a mango-avocado side salad, and less yes to a deep-fried ice cream sandwich. But there's a reason I said "less yes," and that's because saturated fats aren't completely off-limits (although a deep-fried ice cream sandwich is still suspect -- keep reading).
"Including saturated fat in moderation can help support optimal testosterone and vitamin D production. Examples of saturated fat include coconut oil, animal fat, and dairy," says Salter.
In other words, you might want to switch out that deep-fried ice cream sandwich for plain Greek yogurt topped with shredded coconut and dark chocolate chips. Which sounds pretty delicious, honestly.
Finally, if you're going to vilify fat of any kind, it should be trans fats. As Salter points out, "Trans fats have been shown to negatively impact heart health and blood lipid levels. Examples include baked goods such as donuts, muffins, cakes, pies, cookies, candy, and other processed foods." (See what I meant about those donuts and ice cream sandwiches?)