1. Does cooking destroy vitamins?
Yes. Vitamins decay with time at a rate dependent on the temperature. Even at
refrigerator temperatures vitamin C decays, for example (in one month, your opened
container of pure orange juice has essentially no vitamin C left in it). Broccoli that is
steamed has half the vitamin C remaining. Other vitamins suffer from the same
problem. Ideally your diet will include uncooked fruits and vegetables in addition to the
ones that are cooked. Note that some canned and frozen fruits and vegetables you get
in the store actually have higher vitamin content than fresh ones, because the fruits or
vegetables were canned or frozen on site where they were picked and do not age as
much during transport to the consumer.
2. Does cooking decrease the fat in food?”
Yes. Whenever you cook, bake, boil, etc any meat and see what looks like an oil
slick in the juice around it, some fat has come out of the meat.
3. How are nutritional contents measured?
By the state of the food at the time of purchase. Meat, for example, is higher in water
content when raw, so as it cooks its caloric density increases. Be careful of labels
saying “2 % fat” on dairy cartons and hamburger packages. This means 2 % by
volume, which correlates to ~ 35 % of the calories coming from fat. Note that most
foods say on their labels “calories” as well as “calories from fat”. In those cases, it is
clear what percentage of the calories are coming from fat. The dairy and meat industry
knows that consumers will assume “2 % fat” will be understood as percent by calories
since most foods are labeled that way. But the FDA does not require percentages to
be reported by calories, only that the total calories as well as the grams of fat, protein,
and carbohydrate are reported. This forces the consumer to look closer at labels and
not go by the large print that is trying to sell saturated fat as if it is health food. Even in
the case of meats and dairy we are susceptible to truth in advertising issues, although
the letter of the law HAS been followed in the advertisements we are discussing here.
4. What should I look for on food labels?
If you are counting calories look at BOTH the calories per serving AS WELL AS the
serving size. You will be amazed at how small the servings are that food companies
assign to their products. For general health look for as high a fiber content as
possible. Fiber is carbohydrate that can not be digested. When a food container says
“10 g of carbohydrate, 2 grams of sugar, and 2 grams of fiber”, this means that the 2
grams of sugar and 2 grams of fiber are PART of the 10 grams of carbohydrate i.e.
there is 6 grams of starch (the remainder). When comparing products of the same
type, go with the highest percentage of total carbohydrates as fiber and the lowest as
sugar. In terms of fat look for low saturated fat content (less than one-third of the total
fat content if possible) and NO trans fats i.e. no partially-hydrogenated oils. There are
now partially-hydrogenated-oil products on the market that do not contain trans fats
because the hydrogenation is done by specific chemistry that does not produce them,
but if a company is going through the effort to use these processes they will typically
have in big letters on their container “NO trans fats”.
Yes. Vitamins decay with time at a rate dependent on the temperature. Even at
refrigerator temperatures vitamin C decays, for example (in one month, your opened
container of pure orange juice has essentially no vitamin C left in it). Broccoli that is
steamed has half the vitamin C remaining. Other vitamins suffer from the same
problem. Ideally your diet will include uncooked fruits and vegetables in addition to the
ones that are cooked. Note that some canned and frozen fruits and vegetables you get
in the store actually have higher vitamin content than fresh ones, because the fruits or
vegetables were canned or frozen on site where they were picked and do not age as
much during transport to the consumer.
2. Does cooking decrease the fat in food?”
Yes. Whenever you cook, bake, boil, etc any meat and see what looks like an oil
slick in the juice around it, some fat has come out of the meat.
3. How are nutritional contents measured?
By the state of the food at the time of purchase. Meat, for example, is higher in water
content when raw, so as it cooks its caloric density increases. Be careful of labels
saying “2 % fat” on dairy cartons and hamburger packages. This means 2 % by
volume, which correlates to ~ 35 % of the calories coming from fat. Note that most
foods say on their labels “calories” as well as “calories from fat”. In those cases, it is
clear what percentage of the calories are coming from fat. The dairy and meat industry
knows that consumers will assume “2 % fat” will be understood as percent by calories
since most foods are labeled that way. But the FDA does not require percentages to
be reported by calories, only that the total calories as well as the grams of fat, protein,
and carbohydrate are reported. This forces the consumer to look closer at labels and
not go by the large print that is trying to sell saturated fat as if it is health food. Even in
the case of meats and dairy we are susceptible to truth in advertising issues, although
the letter of the law HAS been followed in the advertisements we are discussing here.
4. What should I look for on food labels?
If you are counting calories look at BOTH the calories per serving AS WELL AS the
serving size. You will be amazed at how small the servings are that food companies
assign to their products. For general health look for as high a fiber content as
possible. Fiber is carbohydrate that can not be digested. When a food container says
“10 g of carbohydrate, 2 grams of sugar, and 2 grams of fiber”, this means that the 2
grams of sugar and 2 grams of fiber are PART of the 10 grams of carbohydrate i.e.
there is 6 grams of starch (the remainder). When comparing products of the same
type, go with the highest percentage of total carbohydrates as fiber and the lowest as
sugar. In terms of fat look for low saturated fat content (less than one-third of the total
fat content if possible) and NO trans fats i.e. no partially-hydrogenated oils. There are
now partially-hydrogenated-oil products on the market that do not contain trans fats
because the hydrogenation is done by specific chemistry that does not produce them,
but if a company is going through the effort to use these processes they will typically
have in big letters on their container “NO trans fats”.
© Clyde F. Wilson
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