All fat contains 9 calories per gram. A gram of carbohydrate contains 4 calories, and a gram of alcohol contains 7 calories. A gram, by the way, is a unit of weight, and 1 gram is about the same weight as a standard paper clip.

An average double-meat hamburger can contain 31 grams of fat. Five grams of fat equals one teaspoon of fat. That means the double-meat hamburger has 6 teaspoons of fat, a little less than half of a healthy daily fat allowance for many people. But, dietitians state, that doesn’t mean you can never eat such a food. Moderation will permit an occasional sandwich like this.

No more than 30 percent of your daily calories should come from fat. So, for a 2,000-calorie diet, 66 grams of fat would be the maximum. To figure your maximum fat intake, multiply the number of calories you eat daily by 0.30. Then, take that answer and divide it by 9. The answer is the maximum number of fat grams you should consume daily.

A typical low-fat frank contains 1 gram of fat and 50 calories. That’s actually less than the standard hot dog bun, which contains 2 grams of fat and 115 calories.

All cooking oils and shortenings are 100 percent fat and contain 13 to 14 grams of fat per tablespoon. But lard contains more saturated fat, which abounds in meats and dairy products and may be more harmful to your heart. Vegetable oils are mostly monounsaturated and polyunsaturated fat, which generally is less harmful.

Surprisingly, switching to turkey will shave only 2.5 grams of fat. That’s because the real culprit in sandwiches are not lean meats but the cheese and regular mayo. By substituting tomato and lettuce for cheese and using no-fat mayo or mustard, you can take the entire roast beef sandwich fat total to 7.5 grams.

One avocado has 30 grams of fat, unusually high for a fruit. More than half of the fat is monounsaturated, but the total includes 4.5 grams of saturated fat. This is still more saturated fat than two slices of Canadian bacon, a lean meat. Eight ounces of buttermilk has only 2 grams of fat.

If you step on the scale daily, you may notice a 2-pound increase, but that’s probably from temporary factors such as water retention, according to the U.S. Department of Agriculture. You’d have to eat 7,000 calories -- that’s about 23 cheeseburgers -- on top of your daily requirement to put on 2 pounds of fat.