What should we eat which is healthy and gives us lot of energy?

Whole foods: Eat whole foods, colorful fruits and vegetables. Eliminate processed foods. Read labels, if a food contains additives avoid it. If you can't read it, don't eat it.

Diet: It seems that for most people a low carb diet is more energy producing. The main reason is that it levels your insulin level. Check into the glycemic index and that will guide you to good foods.

No easy answer but:: No single diet is best for everyone but I advise mostly organic vegetables & fruits & quality protein like organic eggs, nuts & wild salmon. Minimize sweets & simple carbs, choose whole grains, minimize fried foods & avoid GMO's. I like Dr. Fuhrman's Nutritarian diet: http://www.drfuhrman.com/library/what-is-a-nutritarian-diet.aspx For my essay on healthy eating see http://tinyurl.com/nq4sx63