Dr. Mark Hyman’s latest book, Eat Fat, Get Thin is a great read, filled with a complete breakdown on different types of fat and the health consequence of consuming each. Delicious fats like those found in eggs, avocados, coconut oil, and nuts should become more a part of our diet according to Dr. Hyman, not only because they promote health but because they also assist in weight loss. He dispenses with the myth that “fat makes you fat” and reiterates and references the points made in Gary Taubes’ books (see our review of Why We Get Fat) , and Always Hungry by Dr. David Ludwig: a calorie is not a calorie, and weight and metabolism aren’t math equations—food is information. “Different calories affect your gene expression, hormones, brain chemistry, immune system, gut flora, and metabolism at every level.”
Eat Fat, Get Thin also covers topics like heart disease, whether people should eat meat from a health perspective, and controversial fats like butter (good if grass-fed), coconut oil (good if unrefined and organic), and refined palm oil (not so good for a variety of reasons). Commercially processed palm oil now accounts for 65% of internationally traded oil, and is what the fast-food industry has used as a substitute for outlawed trans fats. The book includes an eating plan designed to implement Dr. Hyman’s diet, and the last third of Eat Fat, Get Thin provides his recipes.
Mark Hyman, M.D. is the medical director of the Cleveland Clinic Center for Functional Medicine, the chairman of the Institute for Functional Medicine, and a New York Times bestselling author of twelve books including, The Blood Sugar Solution. He is a former vegetarian who now consumes red meat several times a month and describes himself as a “pegan” (a term that embraces both paleo and vegetarian diets).
Below is a summary and highlights of the section of the book covering the science on fats.
WHY WE OVEREAT
The author ascribes to Dr. Ludwig’s theory that, being fat is what actually makes us eat more and exercise less—fat cells get starved and contribute to overeating. “When you are overweight, your hormones and brain chemistry make you hungry and tired.” The conventional “wisdom,” that eating more and exercising less is what makes you fat, is backward.
WHY WE GAIN OR LOSE WEIGHT: BIOLOGY OF FAT CELLS
Fat cells produce hormones; fat tissue is also a part of your immune system and can produce “inflammatory messenger chemicals.” It is a storage organ and can even produce more fat (using carbohydrates in the diet). “Most of the biology of fat cells in controlled by quality and type of the food you eat.”
HIGH-FAT VERSUS LOW-FAT DIETS
The general consensus is that high-fat, low-carbohydrate diets work better than low-fat, high-carbohydrate diets, which is supported by the following studies:
The A-Z Weight Loss Study, published in the Journal of The American Medical Association (2007). Three-hundred and eleven overweight non-diabetic post-menopausal women were studied for over 12 months. The high-fat group did better in every way, losing twice the weight and saw improvement in every cardiovascular risk factor. (p. 59)
The Cochrane Collaboration, a global independent group of researchers and patients who received no money from industry or government included findings from Harvard researchers that looked at 53 randomized controlled trials lasting a year or more (published in 2007). Weight loss worked much better with high-fat, low-carb diets when compared “head to head” with low-fat diets. (p. 61)
LOW-FAT DIETS MAKE YOU CRAVE BAD FOODS
The author cites the schoolchildren study referenced and reviewed in Always Hungry. Scientists gave either unlimited cheese or potato chip snacks to 6th graders, and found that the potato chip group consumed three times as many calories. And when the cheese was combined with vegetables, the “cheese group” ate even fewer calories.
A PRIMER ON FATS
Fats, or fatty acids, are made up of a chain of carbon, oxygen, and hydrogen atoms with another group of the same atoms at one end. They are classified according to how many carbon atoms are in the chain, as well as how many double bonds exist within the molecule. There are short and long-chain fats, and fats with double bonds like polyunsaturated fats, or no bonds like saturated fats. Fatty acid molecules that are joined in groups of three are triglycerides, which are made in our liver from carbohydrates.
There are four types of fatty acids:
- Saturated (SFA)
- Monounsaturated (MUFA)
- Polyunsaturated (PUFA)—either omega-3 or omega-6
- Trans fats (TFA)
The fat content of a certain food may be made up of several different types of fatty acids. For example, butter is 60% saturated fat, and 40% mono and polyunsaturated fats.
SATURATED FATS (SFA)
“Dietary saturated fats don’t raise blood saturated fats. It is carbs and sugar (and excess protein) that cause your liver to produce the saturated fats found in your blood.” (p. 74)
According to the author, saturated fat from coconut oil or grass-fed butter strengthen the immune system, and help suppress inflammation. Saturated fats assist with brain function (see Grain Brain). Only when saturated fats are combined with refined carbs or sugar (or when you don’t consume enough omega-3 fats) does inflammation result.
MONOUNSATURATED FATS (MUFA)
These fats are good for you. They include the fats found in nuts, whole olives, olive oil, avocados, certain fish, and dairy and animal foods (remember fat content of some foods can be made up of different kinds of fat, and meat is no exception). Cardiologists routinely recommend eating a Mediterranean diet because of the high monounsaturated fat content. These fats contain Vitamin E and other antioxidants and can improve insulin sensitivity.
Canola oil should be avoided because it is produced by “applying high heat and harsh chemical solvents in the refining process.” (p. 77) Use extra virgin olive oil whenever possible.
On a personal note: for an occasional meal requiring a high-heat oil, I cook with expeller-pressed Spectrum Organic Sunflower Oil (this brand is 11 g monounsaturated fat, 1.5 g polyunsaturated, 1 g saturated fat); it is refined, as are most all high-heat oils, but without solvents—it can be heated to 460 degrees. At times, I also use a non-gmo rice bran oil that can be heated to temperatures ranging from 400-450 degrees; it contains slightly more monounsaturated fat than polyunsaturated fat.
POLYPOLYUNSATURATED FATS (PUFA): OMEGA-3 AND OMEGA-6 FATTY ACIDS
Omega-3 and Omega-6 fatty acids are essential—we need them in our diet and they can’t be produced in our bodies. Scientists call these fats “essential.”
“PUFAs play a key role in cellular, immune, and hormonal function…omega-3 fats…make up much of your cell membranes and regulate insulin function, inflammation, and even your neurotransmitters which is why they are critical for preventing and treating diabetes, depression, arthritis, and autoimmune disease.” (p. 77)
Omega-3 fats are the type of fat that is very lacking in the standard American diet, and is vital to good health. Medium-chain omega-3 fats are comprised of ALA, alpha linoleic acid, and long-chain omega-3s that are made up of EPA and DHA.
Medium-Chain Omega 3 fats from ALA are protective for health and can be found in flaxseeds, walnuts, hemp and chia seeds, and green leafy vegetables.
Long-Chain Omega-3s are found in cold-water fatty fish like sardines, trout, salmon, anchovies, oysters, and tuna (eat in moderation due to mercury content), grass-fed cattle and algae.
My fish oil supplements are Spectrum brand that contain 320 mg of EPA, and 200 mg of DHA, from sustainably harvested anchovies, sardines, and mackerel. More than 90% of Americans are deficient in these essential fatty acids that were an important part of our “evolutionary diet.”
Omega-6 fats tend to cause inflammation, are easily oxidized and go rancid, but not all are bad. On the other hand, omega-3 fats are anti-inflammatory, and it is the consumption ratio between omega-6 fats and omega-3 fats that is important. The ratio should be 1:1 or at the most 4:1 (4 omega-6s to 1 omega-3). When we consume too many omega-6 fats in processed food, corn and safflower oils, the immune system is suppressed, and weight gain occurs, along with inflammation.
I had my ratio measured several years ago and I consume four times as many omega-3s as omega-6s—a result of daily “scavenger hunting” for the best foods I can use to fuel my body.
Medium-Chain Omega-6s: Linoleic Acid (LA) is the most abundant fat in our diet and is most dangerous when used for frying, especially frying foods containing carbs (think French fries). Linoleic acid is made mostly from soybean oil, and accounts for 90% of all polyunsaturated fat consumption in the U.S.
Long-chain Omega-6s: Arachidonic Acid (AA) is found in eggs, beef, poultry and liver. Wild and pasture-raised animals have a good ratio of AA to omega-3s, whereas industrially-raised animals have more AA and very little omega-3s.
TRANS FATS (TFA)
These man-made hydrogenated fats are found in processed food, margarines, fried foods, and commercially produced baked goods; the FDA has ruled they are “unsafe to eat” as of 2013. (p. 84)
Watch out though—a product can be labeled “trans fat free” if it contains less than .5 grams per serving. Cool whip, for example, is made up of trans fat despite its label to the contrary, because it’s mostly air. (p. 84)
THE SURPRISING TRUTH ABOUT FAT AND HEART DISEASE
THE BREAKTHOUGH ON SATURATED FATS
In 2014, a review of 72 of the best studies on heart disease and fat was published. This meta-analysis included more than 600,000 people in 18 countries and appeared in the Annals of Internal Medicine, established by the American College of Physicians. The conclusion was that “there was no link between total fat or saturated fat and heart disease.” (p. 92) In seventeen of the studies, blood levels of different fats were even measured, a better indicator than dietary recall. The study also showed that “omega-3 fats from fish or supplements were the most protective against heart disease.” (p. 93) And there was no benefit from the omega-6s in vegetable oil; “in fact, it showed that these tend to cause heart disease.” (p. 93)
SATURATED FATS AND INFLAMMATION
“There is some evidence that saturated fats cause inflammation in humans…and inflammation is an underlying cause of hear disease, obesity, type 2 diabetes, and dementia.” (p. 96) This inflammation only appears to occur when there are low level of omega-3 fats and high levels of carbohydrates. But when a diet is composed of low-carb, high-fiber, high-omega-3 fats, saturated fats can lower inflammation.
SATURATED FATS AND CARBOHYDRATES
A recent study at Ohio State University tested overweight pre-diabetic subjects for 18 weeks. In the first part of the study the carbs were increased from 50 to 350 grams a day, and the saturated fat was reduced. In the second part of the study, the saturated fats were increased from 46 to 84 grams a day, but the carbs were reduced. Higher levels of saturated fat in the blood only occurred during the high carb part of the diet.
SATURATED FATS AND CHOLESTEROL
Most of the cholesterol in your blood is made up in the liver. “The liver gets triggered to produce fat and cholesterol in response to sugar and carbs….High carb diets increase the production of triglycerides, lower good cholesterol (HDL), and increase the number of [small] LDL particles.
This kind of lipid profile is called atherogenic—in other words, it causes atherosclerosis, or hardening of the arteries, the very thing at the root of heart disease, stroke, and in many cases of dementia.” (p. 100)
The type of fat you eat is of greater consequence than the amount of fat when examining cholesterol. Trans fat and refined vegetable oils contribute to abnormal cholesterol, and omega-3 fats from fish and monounsaturated fats improves cholesterol. “In reality, the biggest source of abnormal cholesterol is not fat at all—it’s sugar. The sugar you consumes converts to fat in your body.” (p. 102)
VEGETABLE OILS—A SLIPPERY SUBJECT
For years the American Heart Association and others have been advising us to stay away from saturated fats and eat polyunsaturated fats instead. Vegetable oils were basically unknown a hundred years ago, but now “thanks to farm subsidies and the power of Monsanto’s global soybean monopoly, Americans consume about 18 billions pounds of soybean oil a year. About 20 percent of our calories come from soybean oil, which is 50 percent linoleic acid, an inflammatory omega-6 fat…..soybean oil is in almost everything.” (p. 117)
The National Institutes of Health scientists who have reviewed experimental (as opposed to observational) studies on omega-6s have made the following findings, referenced on (p. 119)
- Where subjects consumed a mixture of omega-3 and omega-6 fats, heart attacks and death was reduced by 27 percent.
- If omega-6 consumption was increased without an omega-3 fat increase, 13 percent more heart attacks occurred.
- Reducing saturated fats and using omega-6 fats without omega-3s resulted in a increased risk of death in randomized trials.
MEAT—DOESN’T IT CAUSE HEART DISEASE AND TYPE 2 DIABETES?
Generally speaking, it appears that it may not the meat that impacts longevity (buffalo-eating Plains Indians have the highest number of centenarians per capita), but the sugar and refined carbs that are often a part of a typical meat eater’s diet.
THE PROBLEM WITH THE RESEARCH ON MEAT
Good research on food is hard to accomplish, and meat is no exception, since most studies are association studies and done by food recall.
The National Institutes of Health AARP Diet and Health Study of 500,000 men and women for 10 years did find “a correlation between meat, heart disease, cancer and death.” They also found that meat eaters weren’t very healthy, consuming 800 extra calories, smoking more, exercising less and eating more sugar than non-meat eaters. But when health-conscious meat eaters where compared with vegetarians in a study of almost 20,000 individuals, the researchers found that overall death rates were cut in half for both groups compared with people eating a standard American processed food diet.
There is, however, evidence to support that processed meats like bacon, hot dogs, and luncheon meats are harmful to health.
DO SATURATED FAT AND CHOLESTEROL IN MEAT CAUSE HEART DISEASE?
The American Heart Association has “debunked” any connection between heart disease and dietary cholesterol, but saturated fat is “still under debate.” While elevated saturated fat levels do cause heart disease only the types of saturated fats that come from eating carbs and sugars,stearic and palmitic saturated fats, are harmful and they don’t come from eating meat.
Studies have shown that feeding obese or heart disease patients a diet higher in fat and higher in good-quality animal protein had better weight, blood pressure, triglycerides, HDL and LDL when compared to diets higher in carbs and lower in fat and meat, even when the calories were the same. (p.131)
DOES RED MEAT CAUSE CANCER?
When lifestyle factors such as smoking, exercise, and weight were factored out, little risk from meat eating was observed in cases of colon cancer (the cancer with most of the data), with the exception of processed meat like hot dogs and bacon.
Cooking at high temperature and charring meat can lead to producing of the compounds called PAHs (polycyclic aromatic hydrocarbons) and HCA, which have been found to cause cancer in animals. But vegetables grilling and charring can also be a source of harmful PAHs.
Red meat does contain compounds that can prevent cancer like omega-3 fats, and nutrients like vitamin B6, B12 and Vitamin D.
DOES IT CAUSE INFLAMMATION?
Meat contains the omega-6 fat arachidonic acid that is in all your cell membranes and help control inflammation in your body. Eating grass-fed meat can keep fats in balance because it increases levels of both omega-3s and “the right” omega-6s.
IS GRASS-FED MEAT BETTER?
Cows have stomachs that are designed to eat grass. When the are fed grains, their levels of omega-6s increase. And since we eat what our food eats, our levels also rise. The ratio of omega-6 to omega-3 fats in grass-fed beef is about 1.5 to 1.
Corn also causes bloating as gut bacteria ferments the corn feed thus requiring the need for antibiotics. Of the 24 million pounds of antibiotics American use each year, 19 million are put into animal feed which has contributed to antibiotic resistance in animals and humans. (p. 141)
CONTROVERSIAL FOODS—WHAT’S GOOD, WHAT’S NOT
BETTER OFF WITH (OR WITHOUT) BUTTER?
“There may be reasons to avoid dairy, but saturated fat content is not one of them.” According to the author, there is no good evidence proving a link between butter and heart disease, and it may even be good for prevention. (p. 144)
Butter is pure animal fat with traces of sugars and dairy proteins. The food the cows’ eat will determine the nutritional content of the butter. Butter is about 60% saturated fat, 20% monounsaturated fat, and 20% polyunsaturated fat. “Cows raised on pasture, produce milk fat with an omega-6 to omega-3 ration of 1:1, which is ideal.” (p. 145) The ratio of omega-6s to omega-3s in grain-fed beef is almost 8:1.
Grass-fed butter has more carotene and Vitamin A than conventional butter, which can store environmental toxins and pesticides.
Ghee—is a type of India butter that has been simmered to remove most of the water and milk solids, leaving the fat. It smokes at a higher temperature (between 400-500 degrees) than traditional butter (between 325-375 degrees) so is useful in high-heat cooking. I buy a high-quality organic ghee from Purity Farms sold at PCC Natural Markets.
“Clarified butter has had water and milk solids removed, so it can be used by those allergic to dairy.” (p. 146)
COCONUT OIL: HEALTHY OR HARMFUL?
Coconut oil has the highest amount of saturated fat found in any food, however, it has not been “correlated with any increased risk of heart attack or stroke.” (p.147) It increases total cholesterol but increases HDL, the good cholesterol, the most thereby improving the ratio of HDL to LDL. And, according to the author, coconut fat is associated with lower insulin levels.
Coconut butter is made from whole coconut flesh with fats and solids—pulverized coconut meat. It is 60% oil and a tablespoon has 3 grams of fiber.
Coconut oil is made from the dried flesh of the coconut. Half of the saturated fat in coconut oil is the rare lauric acid, which is a medium-chain triglyceride (MCT). “In the body, lauric acid converts to monolaurin, one of the compounds found in breast milk that boost a baby’s immune system (as do antibodies and colostrum).” (p. 147)
A diet high in MCTs (medium-chain triycycerides like coconut oil ) was shown to increase more energy and fat burning than a diet rich in long chain-triglycerides (LCT) like olive oil in a “cross-over” study published in Obesity Research in 2003. In a small study that compared the impact of MCTs and LCTs (this one was with corn oil) on metabolism measured in terns of oxygen consumption, a meal rich in MCTs produced an increase of 12%, triple that of the LCT meal. (American Journal of Clinical Nutrition, 1984.) This study also found that blood levels of triglycerides increase by 68% after a meal with corn oil, where there was no increase after the MCT meal. (p. 148-149)
MCT oils get absorbed directly from the gut to the liver, and are burned quickly; “omega-6 fats… like corn, soy, sunflower, and canola—are transported into the lymphatic system, not the blood, which allows them to be taken up in your fat tissues.” (p. 149)
Buy coconut oil that is virgin, organic, cold-pressed, unrefined, that smells of coconut (not deodorized or bleached). I use Nutiva brand which is sold at PCC Natural Markets and Whole Foods. It is 65% saturated fat. Their label states: no refrigeration is required; solid at room temperature and melts at 76 degrees F.