I always steer people into eating minimal ingredients. The basics such as fresh meats, vegetables, fruits.
Your ingredients should be made up of whole foods, whether your lunch contains a meal made of 5 ingredients or 20.
For instance, instead of pre-flavored yogurt, buy plain yogurt and add your own fresh fruits into it, or granola. This way you are buying the yogurt from it's most refined state, and building your own ingredients.
When I grocery shop theres literally no cardboard in my shopping cart, almost no packages. I spend 90% of my time in the meats section, and then straight over to the produce. Those are your whole foods, how you combine them afterwards is up to you. But your already off to a much healthier start.
The more time you spend shopping on the outer perimeter of the store, generally the healthier your shopping. I you think about that statement, it makes sense. Stay out of the interior isles as much as possible aside from spices, pasta, and some other things.
People tend to over think a diet, it's all about micronutrients and macronutrients and I encourage everyone who wants to better their life to lookup those two terms. Read about them, learn them. Your either losing weight, maintaining weight , or adding weight to your body. In order to do ANY of those you need to understand what macronutrient numbers you need daily to meet your goal for your body weight, whether that be maintaining your current weight, losing weight, or gaining.
Either way, without even getting into the macros and micros...if you just stick to eating more whole foods, you will be a healthier eater.
Some argue that it doesn't matter where your macros (such as calories) come from, as long as your sticking to your target number you need for your goal, it's even debatable that it's scientifically proven that it doesn't matter what you eat, it's about balancing it. For example you can eat Burger King as long as it's not going to put you over your daily calories or saturated fat numbers etc.. It is said that your body doesn't care what your numbers come from whether it's Burger King, or it's Subway....the problem is people eat too much of it too often. You can eat whatever the hell you want as long as at the end of the day your Macro's and Micro's are hit.
Me personally, I like eating more traditionally, basic whole foods. Despite my body not really caring where my numbers come from, I feel better personally eating a strict diet.
Cut the processed foods out, stay away from the deli meats, and keep your ingredients simple.
Oh, and get a juicer and pick up apples, carrots, celery etc....those things alone make you feel like a million dollars once you start regularly drinking them.
Bottom line is if people just took the time to educate themselves on nutrition specifically macronutrients, dieting would be a non issue for those willing to stick to one.