American poet Walt Whitman may have written "Leaves of Grass," but he was an advocate of what he called a "manly" diet. "Let the main part of the diet be meat, to the exclusion of all else," he wrote in a newly discovered essay.

Well, Walt apparently didn't know that diets without a balanced approach to nutrition can leave you starved for essential nutrients.

For example, the paleo diet (lots of meat proteins, saturated fat, and vegetables) is devoid of whole grains, such as fiber to feed your gut biome, regulate blood sugar, and battle obesity. It also lacks lowfat dairy and legumes (beans, lentils, etc.).

That can leave you short of B vitamins, calcium, and vitamin D.

One-quarter of folks now eat gluten-free foods, which according to the Institute of Food Technologies means they’re not getting the fiber and nutrients found in 100 percent whole wheat, barley, and rye.

The smart move: Get complex carbs and nutrients from produce and gluten-free quinoa, brown rice, amaranth, buckwheat groats, corn grits, millet, sorghum, wild rice and teff. And remember, apples, carrots, fish, and almonds are gluten-free ... but a gluten-free cookie is still a cookie.

Pay attention to the nutrient content of foods and ask your doc about taking a multivitamin, DHA, and omega-3.

Then, as Walt also wrote, you'll enjoy, "The feeling of health ... the song of me rising from bed and meeting the sun."