Much of society is putting on ounces and pounds in places they'd prefer not to. Is fat the culprit? Well, yes and no. Depending on the kind of fat you eat, you may either end up carrying that fat on your behind or – and here's the exciting part using it as fuel.

Does that mean we can order a hamburger and french fries without feeling guilty? Yep, but only seldomly; that weekly Big Mac attack is probably way too much. Okay, we know that if we eat too many calories, we'll get fat, and if we eat too much fat, we'll gain fat more easily. But did you know that if you eat the right" kind of fat, you may not get as fat as you might expect? That's great news – and researchers from Curtin University of Technology in Perth, Australia, conducted an animal study to verify what we seem to find in humans.

The researchers fed 69 female mice one of three diets: low-fat (11.5% of calories from fat), beef (saturated) fat (40.80% of calories from fat) or monounsaturated-fat canola oil (40.8% of calories from fat). Each diet contained the same amount of protein, vitamins, minerals and fiber per calorie. Then to make things a bit more complicated, they divided each group into exercising and non-exercising subgroups.

After eight weeks of treatment, the researchers found that non-exercising mice that ate beef fat gained the most body-fat. These mice had 23.2% body fat, the mice that ate canola oil had 16.8% body fat, and the mice on the low-fat diet had 13.9% body fat. Not surprisingly, exercise brought the body fat percentages down for all groups (beef-fat mice, 12.6% body fat; canola mice, 9.6% body fat; low-fat mice, 7.4% body fat). Interestingly, the total lean body mass of each group was nearly identical, regardless of diet or exercise.

So what should we make of this study? Well, mostly saturated fats, like beef fat, are definitely something you want to limit. This stuff is more easily stored as fat, regardless of exercise, not to mention associated increases in blood lipid levels, formation of plaque and artherosclerosis. Now, eating the same amount of fat calories in a mostly monounsaturated source (for example, canola or olive oil, etc.) will result in less fat deposition and fewer negative health consequences. Yet keep in mind that part of the reason the mice that ate a low-fat diet gained the least amount of body fat was because they had the lowest energy consumption. So don't he fooled into thinking you can just dump a gallon of olive oil on a salad and not get fat.

In addition, exercise plus a low-fat diet is obviously best for maintaining single-digit percent body fat. But for those individuals who succumb to a food fest filled with fat, you're better off with the olive and canola oils. Not only will you be helping your appearance, but also eating the monounsaturated (and even polyunsaturated) oils will further reduce your risk of cardiovascular disease.