Read the nutrition labels. Look for nutrition Facts table on prepackaged foods. You can find out if certain food contains trans-fat and how much of it by reading the label. 
The table provides information on calories, fat, saturated fat, trans-fat, cholesterol, sodium, carbohydrate, fiber, sugars, protein, vitamin A, vitamin C, calcium and iron. The label also shows the % Daily Value which is amount of nutrient in a serving of the food as a percentage of the daily recommended amount. For example, if the label says Total Fat 20%, it means one serving of the food contains 20% of your total daily recommended amount of fat intake.
Low-fat, low-sugar, low-carbohydrate, “light” and “diet” do not mean they are low in fat or calories. Food with low-sugar label can still contain too much fat and a lot of calories. You can find out how much fat or calories it really has by reading the nutrition label.
I used to drink those tomato juice and vegetable juice in a can. I thought it was a great way to easily increase my vegetable intake. One day, I read the nutrition label on the can of the vegetable juice I was drinking. There were about 700 mg of sodium in one can or 30% of the daily recommended amount. It was too high. I guess they have to add a lot of salt to preserve the freshness of the juice but that amount of salt is bad for my blood vessels (it will harden the blood vessel and make it less likely to hold the pressure and easier to burst) so I quit drinking those. From then on, I buy fresh apples, banana, celery, kiwi, carrots and tomatoes to make my own health drink.
