Everyone is different. Your genetics has something to do with what works for you. So this is my spin. I cannot eat a lower-carb/higher-fat diet like some here do - it simply does not work for me. I tried it and I felt like shit. I gravitated over time to eating a more higher-carb (complex carbs ONLY!) with moderate fat, and low-to-moderate protein. I feel absolutely great eating that way, my lipids test results are awesome, I have good energy and stamina, and so on. I will never be a body-builder type like some on this board, so what works for me likely will not work for them.
As Gene said in another thread - avoid processed carbs and added sugar. Hell - I do not buy anything from a can or a box in general. NO fast foods. I've not been to any fast-food places in nearly 3 years. No sodas. I don't do milk either - only fermented grass-grown products such as yogurt or aged cheese from a local dairy. I also do not eat any wheat based products because I appear to have a gluten sensitivity. But nothing wrong with true heirloom whole wheat-grain based products that are more stone-ground at a lower temperature and slow-fermented but you won't see this stuff in the stores. It's the industrial wheat crap that is bad as they strip off all the fiber and nutrients with the fast high-temperature processing.
I eat clean: veggies are the priority for me, fruits, lean grass-grown meat (I just found a guy who sells elk - wow is that a tasty great lean meat - my favorite), wild-caught sustainable fish. Get good healthy fats from nuts/seeds/avocados. I also eat non-wheat grains such as quinoa/buckwheat (technically they are seeds, not grains) and a lot of beans.
Don't get so caught up in these fad diets (paleo, low-carb, vegan). I see people twisting themselves in knots worrying if they are eating paleo for example, or some vegan claiming he vomited because he accidentally ate some bacon. Americans are particularly prone to fad diets, we seem to be a culture of needing authority figures to tell us how to we should eat. Which is why we see BS such as the "Blood-type diet", or the "Grapefruit diet". Almost all these diets are invented by people with agendas and are based on cherry-picking of the evidence.