Denmark recently enacted a fat tax of about $1.50 per pound on food that contains more than 2.3 percent saturated fat. (Bigstockphoto/BIGSTOCKPHOTO)

You probably know that eating lots of high-fat food comes at a price: a thicker waistline and, if you load up on saturated or trans fats, an increased risk of heart disease and other problems. But what if you literally had to pay to eat fat?

That’s happening in Denmark, where, in an attempt to improve public health, the government recently enacted a “fat tax” of about $1.50 per pound on food — such as bacon, butter, fast food and pastries — that contains more than 2.3 percent saturated fat.

There’s no such plan in the works in the United States, but there are plenty of other reasons to limit the calories in your diet that come from fats and certainly those from saturated fat. The simplest one is that all types of fat, even the healthful ones, contribute a lot of calories: nine per gram vs. four in a gram of carbohydrates or protein. That’s significant if you’re trying to lose or maintain weight.

At the same time, foods with both fat and protein can actually help prevent you from overeating, since they keep you feeling full longer. And some fats, like the omega-3 fatty acids in fish, can lower blood pressure and provide other health benefits.

Here’s a rundown of some of the latest research on how different fats affect your health.

Fat and your health

A fatty diet was once considered a first-class ticket to heart disease. But later research revealed that the situation was far more nuanced. There’s strong evidence that eating monounsaturated and polyunsaturated fats, found in foods such as wild salmon and trout, nuts, avocados and most vegetable oils, actually cuts the risk of heart disease and other problems. For example, a 2011 review of 50 studies found that the Mediterranean diet, which is rich in healthful fats, was linked to a more healthful waist circumference, better blood pressure, improved HDL (good) cholesterol and lower triglyceride levels compared with various other diets. Other research has suggested that people who regularly cook with olive oil and use it as dressing are less likely to have a stroke than do those who never use it.

Saturated fat, on the other hand, is problematic because it kicks your body’s production of cholesterol into overdrive. That’s why limiting this fat, which is found mostly in animal foods and plant sources such as coconuts and palm oil, is a key lifestyle measure for people with heart disease. And a June 2011 study suggested that a diet low in saturated fat and refined carbohydrates could reduce a person’s risk of Alzheimer’s disease.

Furthermore, recent research suggests that cutting back on saturated fat shouldn’t be your only strategy. It’s also smart to increase your intake of food that has cholesterol-lowering properties. In one six-month study, for example, people who reduced their saturated-fat intake while also consuming a diet heavy in plant sterols, soy protein, fiber and nuts reduced their LDL (bad) cholesterol levels more than those who focused only on cutting saturated fat. And a recent review of 48 studies concluded that replacing some saturated fats with more-healthful ones reduced the risk of cardiovascular events by 14 percent.

Trans fat: always bad

There’s no controversy when it comes to trans fat. Found in partially hydrogenated vegetable oil, it both increases LDL cholesterol and decreases HDL cholesterol. High intake has been consistently linked to an increased risk of heart disease. It also may raise the risk of depression, according to a 2011 study of 12,059 adults.

Trans-fat consumption has declined since 2006, when it became mandatory to list it on labels. But you can still find it in some margarines and baked goods. And food labels that show zero grams of trans fat can still contain up to 0.5 grams per serving. So check the list of ingredients for partially hydrogenated vegetable oils.

Copyright 2012. Consumers Union of United States Inc.