Bang for your Buck

Let's face it.  Produce costs a lot, and it isn't getting any cheaper.  You would probably shop around for the best deal on a TV to get the most out of your money, and you're likely to take care of it so it doesn't get ruined.  When you buy fruits and vegetables, you are buying nutrients.  Shouldn't you try to get the most out of your food, too?  First, you need to buy the freshest possible foods.  Next, store it properly and don't forget about it.  Food loses nutrients over time.  Finally, you need to learn how to prepare and cook it in ways that preserve the delicate nutrients.

All fruits and vegetables start losing nutrients as soon as they are harvested, and should be used within a few days of purchase.  They also lose more nutrients once they are cut, so prepare them right before you eat them, and use pre-packaged goods as a last resort (they are, after all, better than nothing).  Frozen vegetables are picked at the peak of ripeness then blanched and frozen before they are packaged.  This locks in nutrients making them a great choice.  Canned fruits are handled in a similar manner, but are stripped of their nutritious peel and often packed in sugar water, making them slightly inferior but still better than nothing.  Canned goods retain most of their nutrients for 1-2 years. 

Should you eat your produce raw or cooked?  More nutrients are present in raw foods; however, vegetables contain a large amount of cellulose which must be broken down before nutrients can be released.  This can be done by chewing, chewing, chewing, or, more easily, by cooking.  Certain compounds such as sulfur (i.e. onions and garlic) and beta-carotene (i.e. carrots) are released and multiplied by heat (cooking), making more health benefits available to the body.  While cooking decreases some nutrients, the body doesn't absorb a lot of the nutrients from the raw form, so eat both.  If you like it raw, eat it raw.  If you like it cooked, by all means cook it, but choose an appropriate method.

Different foods take better to different cooking methods.  This should be considered when choosing how to prepare your food.  You should also take into consideration that nutrients are lost when exposed to heat, submerged in water, and simply over time.  So the worst thing you can do is submerge something in boiling water for an extended period of time.  All cooking methods have their advantages and disadvantages.  In general, the best cooking methods are as follows, from best to worst:

Pressure cooking, Steaming, Microwaving : Basically these are different methods of steaming.  The disadvantage is that any time you use water, even if the food is not submerged, there is some nutrient loss.  But these methods typically call for shorter cooking times and/or lower temperatures which are the main factors in nutrient retention.  Microwaving is fastest but produces less desirable results. 

Sautéing, Stir-frying: Yes, if you use oil, it will add calories.  But it also adds flavor, which goes a long way in encouraging consumption.  Use a small amount of healthy oil like olive or canola, and cut the vegetables into small, thin pieces (not too far in advance or nutrients are lost to by oxidation) so that cooking times are shorter.

Baking, Grilling/Broiling, Roasting: Certain vegetables (root vegetables, squash, potatoes) taste best this way.  The advantage is that there is no water to lose nutrients to, but the disadvantage is the prolonged exposure to heat and higher temperatures.  However, vegetables that are roasted tend to have fewer heat-sensitive nutrients, with the exception of vitamin C which is not lacking in most diets.  Plus the flavor of roasted vegetables is typically good enough to prompt higher intake, making up for the nutrient loss. 

Boiling: One of the worst cooking methods, it can reduce nutrients up to 75% in some vegetables.  It is almost never a recommended cooking method.  An exception is if you will be using the cooking water in a soup or sauce, or drinking it.  Then you will still be getting the nutrients.

Frying: Not recommended for the same reasons as boiling, plus it adds a lot of fat calories with less recourse to recover the nutrients.  The advantage is that pretty much everything tastes awesome when it's fried, especially if it has been battered or breaded.  You will still be getting fiber from the vegetables, but the decrease in nutrients combined with added calories makes this is a "once in a while" preparation method. 

It should be noted that in a taste test among children, the kids preferred vegetables that were either sautéed or roasted.  Those that were boiled or microwaved were the least liked.  When choosing the best preparation method for your fruit or vegetable, keep in mind that you have to eat it to get the benefits, and you might as well enjoy it while you're at it!