I like to use the acronym C.H.O.W. when it comes to food choices. This stands for Clean, Humane, Organic, and Whole. If we aim for these qualities when we shop, we'll be consuming the healthiest and most sustainable versions of our favorite foods. Please note that these are goals: it would be unrealistic to limit yourself to just food that meets all these criteria. Rather than focus on what we (and others) shouldn't be eating, let's all get along and demand clean, humanely raised food that's kind to humans, animals, and the planet. After all, eating and sharing a meal should be a joyful time - not a battleground!
Treat packaged and processed foods with caution! A quick glance at the ingredients will let you know if the product contains artificial additives. Watch out for sweeteners like aspartame, colors with a number (like red 40), or flavor enhancers like monosodium glutamate.
It's a sad fact that the majority of animals on factory farms live in horrendous conditions. However, many labels (meant to reassure us) are quite meaningless: the term "natural" only refers to how a product is processed after slaughter and has nothing to do with how the animal was raised. Thankfully, there are third-party certifications that ensure kinder and more humane practices are followed. If you can find it, Animal Welfare Approved has the highest standard, but enrollment is limited. Certified Humane is more readily available and worth seeking out. And Whole Foods has it's own Global Animal Partnership certification (this is a 5-step program that you can read about at the meat counter). Most animals are fed grass at some point in their lives, so look for 100% grass-fed for the healthiest beef. I found some at Trader Joe's that was very reasonably priced. You can find out where grass-fed meat and dairy products are sold in your state at the Eat Wild and American Grassfed Association websites.
Not everything has to be organic, but it's preferable when it comes to grains, dairy, and certain fruits and vegetables. To find out which produce contains the most pesticides, check out the EWG's (Environmental Working Group) annual Dirty Dozen. And to find out what's okay to buy conventionally grown, see their Clean Fifteen. Don't waste your money on organic fish as there's no certification for this and it isn't regulated. You may have heard that wild salmon is better for you than farmed, and many studies support this. The Oceana Sustainable Seafood Guide is an excellent resource for everything fishy.
This category goes a step further than clean - it's unprocessed food that hasn't had most, or all of its nutritional components stripped away. Bread is the perfect example of this: White bread is mostly starch and is missing the vital fiber and nutrition of 100% whole grain bread. If you include them in your diet, choose whole grains, whole eggs, and yes, whole milk too.
The golden rule is to eat a variety of (nutritious) food in moderation. Too much of a good thing is still too much (as I discovered after eating a ridiculous amount of cherries recently!) It's an unfortunate fact that organic and humanely raised food usually costs more, but when you can find it and afford it, it's an investment you wont regret.
Consuming food in its most natural state is the most straightforward road to better health - and keeping it simple will keep you sane!
Links and References
Animal Welfare Approved
American Grassfed Association
Global Animal Partnership
USDA National Organic Program (NOP)
Eat Wild: Getting Wild Nutrition from Modern Food
Healthline: Best Fish to Eat
Oceana: Sustainable Seafood Guide
Although I have no formal education in nutrition, I've been researching this subject for over forty years. Healthy eating is my passion, and I love to share what's worked so well for me.