Weight Loss

The truth about cholesterol and fat

by Marcelle Pick, OB/GYN NP

Like so many of my patients, for years I tried one low-fat, low-cholesterol diet after another. But after failing to lose weight — and feeling pretty bad despite my “healthy diet” — I did a panel of blood tests on myself. The results were shocking.

That fateful day was 25 years ago. It began my personal search for the truth about cholesterol and fat. What I learned at first surprised me, but now makes perfect sense. And I’ve proven it all in practice, both personally and with thousands of patients.

What surprises me today is that there is still so much confusion about cholesterol and fat. Over 70% of my new patients are still afraid of eating fat — any fat. They think eating fat will make them fat and raise their cholesterol. They think a low-fat diet will help them lose weight and help prevent heart disease.

Unfortunately, none of that is true. In fact the opposite may be true, especially for women. So let me share with you what I tell my new patients about cholesterol and fat. You may be in for a surprise.

Don’t feel guilty about cholesterol and fat

In my low-fat phase, I always used to feel guilty about enjoying fatty foods. But I learned that the human body is hard-wired by evolution to crave cholesterol and fat — so don’t feel guilty!

You crave cholesterol and fat because they’re essential to your health. When you eat real cholesterol and fat, you regulate insulin levels and trigger enzymes that convert food into energy. Cholesterol from food modulates your body’s internal cholesterol production and protects liver function.

What are essential fatty acids (EFA’s)?

Before we get into the role of fat in the body, let’s touch upon the most important type of fat you need to feed yourself. Without a doubt, essential fatty acids are just that — essential. They cannot be synthesized in the body and must come from dietary sources. However, while only two of the fatty acids are technically “essential,” all omega-3 fatty acids are in critically short supply in the average American diet for the following reasons.

Some fatty acids, in particular the omega-3’s, lower triglycerides and soothe inflammation, helping the liver convert pro-inflammatory blood acids like homocysteine into anti-inflammatory agents. The omega-6’s generally play a pro-inflammatory role, but there is evidence that at least one omega-6 fatty acid (gamma linolenic acid, or GLA), found in black current and evening primrose oils, also prevents negative inflammatory effects. Without getting into the biochemistry in too much detail, what is important to note here is that your body works as a seamless, well-greased system when the ratio of one type of fatty acid to another is in balance.

By “balanced,” I mean that over millennia, we humans evolved while eating dietary fats in proportions available to us in our food sources, and came to function optimally on this ratio. In the past 70 or so years, this ratio has changed drastically in the modern diet, contributing all sorts of mischief to our health in the form of obesity, cardiovascular disease, and multiple other chronic degenerative diseases.

Let’s elaborate for a moment on that ratio. For optimal health, humans need a ratio of omega-6 to omega-3 fatty acids somewhere between 1:1 and 4:1. Unfortunately, the typical modern diet provides us with a ratio of way too much omega-6 — between 11 and 30 times the amount we need! Because we must feed these essential nutrients to our body in the correct proportions to support normal cell growth and repair, that means we must either radically change the source of fat in our diets or else supplement our intake of omega-3’s to a significant degree.

What’s the easiest way to do that? See my list of recommendations below for how to get the best kind of fat, but briefly, eicosapentænoic acid (EPA) and docosahexænoic acid (DHA), both found in fish oils and algae, are the two omega-3 fatty acids most highly recommended in supplemental form, and have all sorts of good things going for them in the way of brain and heart health.

So what else is good about fat?

Cholesterol is the mother of all fat molecules in our bodies. We literally run on the stuff. It maintains neurotransmitter and brain function, builds brain and nerve tissue, and nourishes the immune system. It provides the insulation around nerves that transmit electrical impulses. It is a keystone of normal cell function and mood regulation and helps us digest fat-soluble vitamins like A, D, E and K. Importantly for women, many of our most important hormones, including estrogen and progesterone, are made from cholesterol.

Our bodies equate fat in our food with safety and security. It’s an evolutionary thing. When we don’t eat enough fat, our brains become preoccupied with how to procure it. This is why most low-fat diets fail — at some point our biological imperative kicks in and we “cheat” or binge. And feel like we’ve failed!

Our brains aren’t fooled by “fake fat” either. Real fat breaks down slowly over 3-4 hours after eating. Eating fat in combination with other foods (especially carbohydrates) slows digestion and signals the brain that you’re full — so you stop wanting more. (You can imagine being hungry after eating a bag of chips — but not after drinking a glass of olive oil!)

Fat substitutes trigger the promise of fat through enzymes in the mouth but never deliver: they don’t break down the same way in the GI tract. Waiting for the real deal, the brain continues to transmit a “still hungry — eat more” message to your stomach.

In fact, there’s good reason why saturated and unsaturated fats are found together in whole food. Again, it has to do the energy stored in the bonds between atoms and our ability to stow enough away to survive famine conditions. And once again, balance is the key. Healthy fats and cholesterol should be part of a balanced diet the way nature intended, including an appropriate ratio of protein, carbohydrates, and vegetables. Healthy people with normal cholesterol levels can get up to 30% of their daily calories from real fat.

Low-fat, low-cholesterol diets disrupt hormonal balance

Low-fat, low-cholesterol diets can be very unhealthy, especially for women. Why? Because all our major hormones are made from cholesterol: estrogen, progesterone, cortisol, DHEA, and testosterone. If we don’t eat enough, our bodies divert cholesterol from our endocrine system to use for brain function and repair. When that happens, it’s almost impossible for our bodies to maintain hormonal balance. Hot flashes, here we come!

Low-fat, high-carb diets can raise cholesterol levels

America has been on a low-fat diet for over 30 years. Yet we’re fatter than ever, we have an epidemic of diabetes, and our cholesterol levels are rising, not falling. One key reason is that low-fat diets can actually disrupt our normal endocrine balance. Here’s how.

Cholesterol is so important to the human body that nature has devised a backup plan in the event your diet falls short — i.e., during a famine. When that happens, your liver steps in to make cholesterol to guarantee your body a baseline level. The high levels of insulin that are released in most low-fat, high-carb diets also trigger the body to siphon off excess blood sugar into the liver to make cholesterol and triglycerides (which are used for energy and fat storage).

In its natural, unstressed state your liver makes 75% of the cholesterol you need. The rest you have to eat — in foods that contain cholesterol like butter, meat, whole-fat dairy products, shellfish and eggs.

If you deprive yourself of cholesterol (and make up those calories in carbs and sugar), your metabolism goes into famine mode and your liver overproduces cholesterol to make up the difference and stock up. This overdrive state can’t shut off until you start eating cholesterol again. So, a low-cholesterol, high-carbohydrate diet can actually lead to high cholesterol!

Blood cholesterol levels also respond negatively to emotional stress, perhaps for similar reasons.

Some health practitioners see high cholesterol levels first and foremost as a sign of liver distress. Others think that problems stem more from the oxidization of cholesterol by free radicals than from the presence of cholesterol itself. Both may be true. In any case, that low-fat diet isn’t making you healthier.

Cholesterol and fat: weight gain and weight loss

Women are told in thousands of ways that high-fat diets cause weight gain. That theory has spawned a whole industry of low-fat foods and diets. But the truth is that dietary fat does not cause weight gain. In fact, low-fat diets are a more likely cause of weight gain because they tend to emphasize carbs and trans fats (more on trans fats in a moment). To learn more, read our article on weight gain.

Just as importantly, low-cholesterol, low-fat diets do not in and of themselves lead to weight loss. Portion control and the elimination of sweets in those diets are very helpful. But taking out fats and cholesterol starves the body of the nutrients it really needs. Your body goes into famine mode, slowing down or even damaging its metabolism, and converting every calorie it can find into fat.

What’s behind saturated fat’s bad reputation?

There are medical studies that appear to show that saturated fat is unhealthy. They blame saturated fat for making blood platelets cling to artery walls, raise blood cholesterol levels and cause atherosclerosis. And it’s true that some people lower their LDL (the “bad” cholesterol) levels and lose weight when they avoid saturated fat. But I think the answer is more complicated and individual.

Generally, when people cut out saturated fat they eat a lot fewer calories. More significantly, they reduce their inflammation levels, which influences health on all levels.

There’s a clue to inflammation in the studies that link red meat to colon cancer. We just don’t eat the same meat our ancestors did. Growth hormones, antibiotics, and environmental toxins like pesticides and heavy metals accumulate in the fat cells of animals. When we ingest their milk or meat we are eating exponentially high levels of these toxins.

Our natural defense to these toxins is low-grade inflammation. But that response was designed to deal with temporary problems. When the triggering factors are ever-present, the inflammation gets out of control. This, and the preponderance of trans fats in processed foods, may turn out to be the real culprit in our epidemic rates of obesity and heart disease — not cholesterol or healthy fat.

The danger of trans fats

Trans fats are artificially hydrogenated oils used primarily to extend the shelf life of food. Extra hydrogen is pumped into polyunsaturated vegetable oils to saturate the carbon molecules in them. Margarine, butter substitutes and any food containing hydrogenated or partially-hydrogenated oils contain trans fats, even if they are not listed on the label. (The government allows products with less than 0.5% trans fat per serving to call themselves trans-fat-free. The problem is that most people eat more than one serving at a time.)

Trans fats have been the “secret” ingredient of a lot of low-fat “health foods,” even though they’ve been recognized by medicine as a health risk since the early 1970’s. Studies indicate that over 30,000 cardiovascular deaths per year could be avoided if we didn’t eat trans fats. Despite these risks, only the most health-conscious consumers currently avoid trans fats. Congress finally passed legislation requiring standout trans fat labeling on every food product by January 2006.

The dangers of trans fats are very real. The USDA can’t even determine a healthful limit because very small amounts appear to be harmful.

And trans fats are everywhere. A large serving of McDonald’s fries contains 6–7 grams of trans fat. A cup of Bisquick contains 4.5 grams. I once told my children that I would buy them any cookie in the store if they could find a brand that didn’t contain hydrogenated or partially hydrogenated oil. After scouring the store shelves — and believe me they looked — they couldn’t find a single one. Fortunately, this is no longer the case — many products in the aisles nowadays contain no trans fats.

(If you haven’t yet seen the movie “Supersize Me,” you really owe it to yourself and your family to rent it. Everyone will have a good laugh but at the same time see dramatic proof of how quickly fast food can de-rail your metabolism.)

Damaged fat and free radicals

High heat used in rendering oil from plants or cooking with such oils creates trans fatty acids, changing the chemical structure of healthy polyunsaturated fats into something very unhealthy. Our bodies don’t know what to do with this damaged fat. Some scientists believe that molecules of the oil actually break off in the digestive tract to become free radicals.

Likewise, when unsaturated oils are left out in the open air for extended periods of time, as they often are in deep fryers and many home kitchens, they oxidize and turn rancid, which also creates trans fats. So even though polyunsaturated oils have been touted as the healthy choice, you have to treat them carefully — and most food suppliers and restaurants don’t.

The true cost of a low fat, low cholesterol diet

When I think of the confusion around fat, I think of Lucy. She’s an average health-conscious woman who reads a lot about nutrition. She’s watching her weight and cholesterol, so for breakfast she has EggBeaters and orange juice; lunch is salad out of a bag (which could be weeks old) with chopped deli ham (processed), topped with a low-fat dressing made from partially hydrogenated soybean oil; and dinner is usually a frozen diet entrée made from unpronounceable ingredients.

Where is the food in that menu? Moreover, where is the fat? In trying to “eat well” — that is, low-fat, low-cholesterol, low-carb — Lucy is actually starving her cells of the vital fats they need to function. Eventually her metabolism will shut down and she’ll be on that slippery slope toward accelerated aging and a lifetime of medication.

Our great-grandmothers ate a diet rich in animal fat for thousands of years out of necessity. It was all they had until polyunsaturated vegetable oils became available at the turn of the century — around the same time heart disease began to increase. Today, the majority of women get their daily fat from salad dressing, and these are often low-fat formulas loaded with unhealthy trans fats and sugar — usually the lower the fat the higher the sugar!

It’s interesting to note that Europeans still eat like we used to, with an emphasis on minimally processed fats, like animal fat and monounsaturated oils instead of polyunsaturated oils. Maybe that’s their weight-maintenance secret!

What’s the best kind of fat to eat and where can I find it?

The best fat comes from natural, preferably organic plant, fish or animal sources with little to no processing. But the differences in the types of fat and how you use them are likewise important. Here’s a quick guide to healthy and unhealthy fats:

• Monounsaturated fats (MUFA’s) come from the fruits and oils of olives, avocados, canola, peanuts, almonds and apricots. The best kinds are cold- or pure-pressed because they are derived without heat (again, heat can create trans fats). These fats are considered to be the healthiest because they lower LDL levels and raise HDL (the “good” cholesterol). See our overview of the Mediterranean diet for more about MUFA’s.


• Polyunsaturated fats are a good source of the essential fatty acids that lower triglycerides and fight inflammation. The best sources are fish, such as salmon, sardines, anchovies, and herring. Good plant sources include flaxseed, canola, soybean, walnuts, and pecans. Essential fatty acids are also found in oil of evening primrose, black current, and borage. All these oils are available at natural foods stores and should be cold and raw when consumed, not used in cooking because again, with the exception of olive oil (which is higher in saturated fat), exposure to high heat and oxygen damages unsaturated fats and creates trans fatty acids. Extreme heat like that used for frying is not safe for most oils — with the exception of coconut and grapeseed oils. Olive oil can be used for sautéing but not frying. (Better yet, avoid fried foods completely!)


• Saturated fat comes from animals and dairy products like red meat, poultry, cheese, eggs, cream and butter, and tropical fruits, like palm and coconut oils. It is solid or semi-solid at room temperature. Saturated fat remains stable at high heat, making it the preferred choice for cooking over unstable unsaturated fats. Generally speaking, the higher the proportion of saturated fat in an oil, the safer it is to cook with.

What you can do now

[Important Note: If you have hyperlipidemia or high cholesterol, you should heal these conditions before following the guidelines below. If you have been prescribed statin drugs, ask your healthcare practitioner about checking your liver enzymes.]

• Eat real, natural fat and cholesterol every day as part of every meal. But do so safely and within reason. Put real butter or cold-pressed olive oil on your potato — it will fill you up and help slow your digestion of carbohydrates. (Better yet, have a sweet potato instead — it has a lower glycemic index and higher nutritional value.) Dip your bread in olive oil. Snack on nuts, nut butters, olives, and sardines. Have a moderate amount of protein at every meal — it’s usually a great source of real, natural fat.


• Read the food label and ingredients list on all packaged foods. If it has partially hydrogenated or hydrogenated oil, throw it away. Look for packaging that guarantees no trans fats — most manufacturers are complying with the new regulation. Be wary of low-fat substitutes for comfort food; many have artificial ingredients to make up for the loss of fat. Pay attention to serving sizes — some manufacturers use an impossibly small serving size to mislead you into thinking the nutritional content is healthy.


• Shop at natural foods stores or in the natural foods section of your supermarket. Many natural grocery stores will not stock food products that contains trans fats. Organic meat, chicken and eggs contain fewer inflammatory factors like growth hormones and pesticides.


• Eat real, whole foods that you cook yourself. Besides being healthier and less expensive, this ensures that you know what’s in the food you’re eating. Restaurants — especially fast food restaurants — still use trans fats, or cook with polyunsaturated oils, because they are cheap and widely available. Most processed foods are loaded with trans fats. Cooking at home can be just as convenient as fast food, particularly if you make a large batch and reheat the leftovers for another meal.


• Be wary of overly processed dairy products. There’s a lot of controversy about pasteurization and homogenization. While we don’t know for sure, it’s possible that this processing damages the butterfats. But raw milk can have its own dangers, so we don’t recommend it, either. As in all things, try to obtain the best quality dairy products from reliable, organic sources.


• Favor cooking methods that use moderate heat, and avoid cooking with unstable vegetable oils. Very high heat methods, such as grilling, can turn even good fat into trans fat. Don’t use any vegetable oil for cooking unless it has enough saturated fat to be stable. Olive oil is the best example, but it should not be used for frying. Some experts recommend using coconut oil when cooking at high temperatures because of its saturated fat content, but be aware that some varieties flavor everything. Grapeseed oil is another option. Both of these oils cost more.


• Store all cooking oils in the refrigerator to avoid rancidity.


• Take a daily nutritional supplement with omega-3 fatty acids. A supplement high in omega-3’s is important for fighting inflammation, maintaining brain and digestive function, and balancing out the ratio to omega-6’s, which are more readily available in our diet.A daily supplement with folic acid and several B vitamins also helps balance and lower homocysteine levels, while vitamin C fights free radical damage and the oxidation of cholesterol in the arteries. (We’ve created our own nutritional supplements that we can recommend to our patients with confidence. Click here for information on our Essential Nutrients and Women to Women’s Omega-3’s.)

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Last Modified Date: 05/25/2011
Principal Author: Marcelle Pick, OB/GYN NP