How you cook your food matters almost as much as what you cook. Small changes in the kitchen can make the same ingredients more — or less — nutritious.
Boiling vegetables leaches out water-soluble vitamins like vitamin C and B vitamins into the cooking water. Steaming or roasting keeps much more of those nutrients in the food. So that pot of boiling broccoli? You're pouring some of the nutrition down the drain.
Tomatoes are a great example of how cooking can actually improve nutrition. The compound in tomatoes that protects your heart — lycopene — becomes easier for your body to absorb after cooking. Canned tomatoes are nutritionally excellent.
When it comes to cooking fats, olive oil is one of the best choices for everyday cooking. It holds up well at medium heat and has heart-healthy properties. Avoid burning or smoking any oil repeatedly — damaged oils create harmful compounds.
Grilling and charring meat at very high temperatures creates chemicals that can be harmful over time. Marinating meat before grilling — even for 30 minutes — can reduce those chemicals by up to 90%.
Frozen vegetables are just as nutritious as fresh, and sometimes more so, since they're frozen right after harvest.