Less packaging means more environmentally friendly and healthier. Packaged, bottled, and processed foods most likely will have some kind of preservative in the ingredients or wrapping.
BPA, for example, an industrial chemical used for food containers like plastic bottles and metal cans, is a synthetic estrogen and has been linked to several ailments, including endocrine system imbalances. These containers and wrappings end up in our landfill and oceans unless diligent recycling is in place.
BPA-free items are now widely available—look for "BPA-free"-marked products.
What else can you do? Shop for foods in the bulk section of your grocery store to cut back on packaging, and use an eco-friendly shopping bag that you can reuse every time you shop.
We are indeed a take-out society, but think of all those take-out containers discarded day after day. Why not bring a delicious, homemade meal to work (in eco-friendly containers!) a few times a week? These little efforts go a long way!