That little touch of tomatoey goodness you dip your fries into and the creamy sauce that makes your chicken salad smooth and tasty may seem like minor grace notes in the symphony of foods you eat every day. But they can cause discord in your nutrition. 

Ketchup was once considered a cure-all for indigestion, jaundice, and rheumatism. Today, the typical American downs about 175 ounces (10-plus pounds) a year of the stuff. And while the lycopene in cooked tomatoes decreases inflammation, cardiovascular disease, and dementia, the way ketchup is usually prepared cures nothing.

Instead, it delivers high fructose corn syrup and plain old corn syrup (8 grams total per tablespoon), which contribute to fatty liver and unhealthy lipid levels in the blood. (You can, however, look for low- or no-sugar and fructose-free ketchup.)

Commercially prepared mayo is also a diet saboteur. It's usually made with genetically modified soybean oil (loaded with omega-6s) as well as preservatives, sugar, and texturizers.

Excess omega-6s in the American diet contribute to inflammation and gut woes. (You can make your own mayo with olive oil, lemon, and eggs if you need a little bit — but don't overdo it.)

The good news is that mustard can deliver flavor to sandwiches, chicken dishes, and salad dressings. And three ounces of it contains a hit of magnesium, some B vitamins, and vitamin A, as well as a dash of amino acids, minerals, and other phytonutrients.

Other good-for-you and good-for-flavor condiments include salsa, hummus, guacamole, tahini, and balsamic vinegar.

For great ideas on how to use these tasty condiments check out my "What to Eat When Cookbook."