Boosting Your Metabolism For Dummies
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Trans fats have been shown to negatively impact proper breakdown of glucose and fat in the body, thereby slowing metabolic rate and increasing fat storage. And not only do trans fats increase your LDL (bad) cholesterol, but they lower your good cholesterol, HDL. Trans fat also increases inflammation in the body which puts you at risk for chronic diseases like heart disease and diabetes.

Solid fats are not healthy, regardless of what you've grown up believing. Margarine replaced butter in many refrigerators over the past several decades. Butter’s saturated fat increased the risk for heart disease, so a slew of margarine products hit the marketplace.

These were made with partially hydrogenated fats, now commonly known as trans fats, which had a hydrogen atom added to an oil molecule so that it became solid like butter.

Partially hydrogenated (trans) fats and solid fats

The food industry loves hydrogenating oils. Partially hydrogenating oils makes them more stable and less likely to spoil. They can also withstand heat without breaking down, making them an economical choice for frying foods in commercial fryers.

Not only is this ideal for fast food restaurants to make French fries, but it’s also ideal for baked goods such as cookies, pastries, pizza dough, and processed snack foods like chips and crackers — not to mention stick margarine.

Margarine was made from heart-healthy fats, so it just had to be healthier than saturated, right? Wrong. Trans fats were deemed to be even more detrimental to heart health than saturated fat from animal products. Both should be avoided as much as possible. In general, solid fats are bad for your health because the more saturated fat a food contains, the more solid it is.

Solid fats include anything that’s solid at room temperature, including:

  • Butter

  • Milk fat (the fat in milk is solid — it’s just dispersed throughout the liquid using a process called homogenization)

  • Lard (beef or chicken fat)

  • Shortening

  • Stick margarine

And these oils from plant sources are high in saturated or trans fats:

  • Hydrogenated or partially hydrogenated oils

  • Coconut oil

  • Palm and palm kernel oil

Cholesterol, good and bad

Cholesterol is another type of fat which naturally circulates in your blood and is formed by what you eat.

Sources of saturated and trans fats in your diet raise the level of LDL (the “bad”) cholesterol in your blood. There are two types of cholesterol:

  • LDL is the “bad” cholesterol that builds up on the inside your arteries and clogs them up, increasing your risk for a heart attack or stroke.

  • HDL is the “good” cholesterol that’s actually protective and helps remove LDL from the blood by bringing it to the liver, which gets rid of it.

Anything from an animal (meat, dairy, and eggs) contains cholesterol. One large egg contains about 185 milligrams of cholesterol, and eggs get a bad rap for this. However, because your body makes its own cholesterol, the cholesterol you eat doesn’t impact your blood cholesterol level as much as people once thought. Saturated fat from foods affects it more, and most of the fat in eggs is unsaturated.

If you do have heart disease, limit your cholesterol intake to 200 milligrams per day and focus on the foods that contain large amounts of saturated or trans fat.

The importance of minimizing trans fats

Many cities across the country have banned the use of trans fats in restaurants, and in New York City, at least, the effort is paying off. Research over the past five years since the ban took place found that the average trans fats in customers meals has dropped by 2.5 grams, from 3 to 0.5 grams.

That’s pretty substantial considering that for every 2 percent extra calories from trans fat taken in daily, your risk for heart disease increases by 23 percent. The American Heart Association recommends taking in less than 1 percent of your calories from trans fat.

Even a product with a food label that says “0g Trans Fat” doesn’t actually have to be trans fat free. The FDA allows a food that has less than 0.5 grams of trans fat per serving to qualify as “trans fat free.” So, even if you’re being conscientious about it, you could actually be eating some without knowing it.

Read the ingredient list of your processed snack and baked desserts for “partially hydrogenated oil” to determine whether there is any trace of trans fat in your product.

Cut back on these solid fats and replace them with heart-healthy unsaturated and omega-3 fatty acids — instead of refined carbohydrates — to improve your metabolic rate and health.

The American Heart Association recommends limiting saturated fats to less than 7 percent of your daily calorie intake. If you’re consuming 1,800 calories per day, then 7 percent of your calories = 126. Divide that by 9, because there are 9 calories per gram of fat, and you get a maximum of 14 grams of saturated fat in your diet.

Top Ten Saturated Fat Sources
Source Contribution to Intake (%)
Full-fat cheese 8.5
Pizza 5.9
Grain desserts (like pies) 5.8
Dairy desserts (like ice cream) 5.6
Chicken dishes 5.5
Sausage, franks, bacon, ribs 4.9
Burgers 4.4
Mexican-based dishes 4.1
Beef dishes 4.1
Reduced-fat milk 3.9

Source: National Cancer Institute, Top Food Sources of Saturated Fat in the U.S. Population, from NHANES 2005–2006

It’s tough to undo dietary habits. For many years, you may have thought that all fat is unhealthy for you and stuck to all low-fat products (even though many low-fat products on the marketplace add refined sugars for flavor). Now they’re telling you there’s a fat spectrum of nutritious and not so nutritious fats. Turning knowledge into behavioral change isn’t easy.

When it comes to minimizing foods that contain trans fat, take it step by step. For example, if you drink whole milk, next time also buy a carton of skim and try to wean yourself off the whole by pouring a glass half with whole, half with skim. Then slowly increase the proportion of the skim milk in your glass.

About This Article

This article is from the book:

About the book author:

Rachel Berman, RD is the Director of Nutrition for, a free Web site and mobile app which provides tools to help people lead healthier lives. A nationally recognized nutrition expert, she has appeared on The Today Show, several local television and radio health segments, and is frequently quoted in print and online publications.

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