Food and nutrition myths debunked by celebrity trainer David Kirsch

In his latest book, "Ultimate Family Wellness," David shares his own story of balancing fatherhood with fitness, and gives his expert advice on how to work out and eat well with the whole family.

Here he debunks some common food myths and explains the health benefits of a variety of delicious foods that can be enjoyed by the whole family for optimal health and nutrition.

Watermelon Despite popular belief that watermelon is made up of only water and sugar, watermelon is actually a nutrient-dense food with a high amount of vitamins such as A and C, minerals such as iron and calcium, and is high in antioxidants. It is also low in calories, has zero fat, and is made up of 92% water, making it super hydrating in the summer heat.

Avocado Avocado is one of my favorite fruits and my daughters and I love avocado in salads, and even in smoothies. But this very tasty, nutrient-rich food contains more fat and calories than more popular fruits such as berries. So is it healthy to eat on a regular basis?

See for yourself: Avocados provide 20 essential nutrients including eight essential vitamins. They also contain approximately 20 to 25 grams of good fat, essential as part of a heart-healthy diet, and are a great source of fiber which helps regulate bowel movements, lowers blood cholesterol levels, and evens out blood sugar.

Eggs Old-school beliefs held that the egg whites contained all the protein while the yolks contained the fat. But recent research has debunked that myth.

A whole egg contains 7 grams of protein, and the yolk itself contains half the protein and most of the vitamins and minerals. Yes, the yolks have cholesterol, but unless you have a history of high cholesterol or heart disease, they won't affect your cholesterol levels. Whole eggs are practically a perfect food.

They are chock full of almost every essential vitamin and mineral, including vitamin D (one of the few foods that has it), omega-3 fatty acids, and vitamins B6 and B12 -- believed to help ward off heart disease.

Nuts Nuts have gotten a bad rap because of their high fat content. But their protein, heart-healthy fats, high fiber, and antioxidant content earn them a place in your daily diet. I often say "less is more," and portion control is key to healthfully enjoying nuts.

Almonds make it to the top of my list, one of the reasons being that compared to other nuts they contain the most fiber and are the richest in vitamin E, a powerful antioxidant. But I also love walnuts, pistachio nuts, pine nuts, cashews, brazil nuts, and hazelnuts.

White potatoes White potatoes contain 5 grams of fiber, 4 grams of protein, 10% of your daily iron, 20% of your daily potassium, and 70% of your vitamin C. They're also known to fight high blood pressure. Make sure to eat the skin -- my favorite part -- and lose the butter and sour cream. Roasted baked potatoes are also my go-to post-workout snack.

Corn Corn's bad rap is due to association with high-fructose corn syrup, a sweetener made from corn that has had all the nutrition and fiber of corn processed out of it.