The recommended intake of nutrient dense vegetables is approximately 5 servings per day, yet as a society we don't always adhere to these guidelines. Eating the suggested amounts, however, may lower your risk for heart disease, cancer, obesity and Type 2 diabetes.
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The way we prepare and cook our vegetables can also contribute to the amounts of nutrients we are actually consuming - by boiling your veggies, you may lose much of the goodness during cooking.
Take broccoli for example, often said to be the healthiest vegetable on the planet. When boiled however, vitamin C and beneficial plant chemicals called glucosinolates and chlorophyll are reduced. Furthermore, a study published in the British Journal of Nutrition in 2002, states that by boiling and not steaming, there was a significant loss of more than 50 percent of folate from broccoli (and spinach). It may be time to start steaming!
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If you intend to use the water from boiling your veggies for a soup or stock, then this is fine, as you're still consuming all those lost nutrients.
I find that steaming my veggies actually tastes better, and it's easier to not overcook them - another way nutrients are diminished. By steaming, the veggies remain crisp, bright in colour, and actually withhold their unique flavour.
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Every cooking method provides diverse health benefits. Some raw veggies are best eaten in their natural state, as their minerals are damaged when heat is applied. Yet some cooked vegetables may be higher in antioxidants that are released during the cooking process. Each vegetable is different, and research is often contrary; therefore it is best to include a variety of raw and cooked veggies in your diet.
Here is a list of vegetables considered to be best eaten cooked (steamed):
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Veggies that may be better raw:
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It's quite easy to increase your vegetable intake by adding more to your usual recipes, having a salad with dinner or mixing them into smoothies.
I like to mix it up and eat raw veggies as snacks - another way to ensure you're getting your recommended daily intake. Lastly, I find that shopping at my local fruit and veg shop is a lot cheaper than the supermarket. Some produce is reduced, as it's not of the highest 'aesthetic' quality, however the look of the vegetable doesn't impact the taste or overall quality.