“The plan you’re putting me on includes lots of nuts, seeds, coconut oil, avocados, eggs, and even some butter,” a patient recently told me. “I can’t shake my fear of fat. I think all this food is going to make me gain weight.”
If you can identify with this patient, you’re not alone. Even I once had a fear of fat while growing up. I subscribed to the antiquated “all calories are the same” myth, a mentality that demonizes fat. After all, eating fat makes you fat, right? End of story.
From a caloric perspective, that makes sense. Dietary fat contains nine calories per gram, versus the four calories per gram for carbs and protein. If you eat less fat, you will eat fewer calories, and you will lose weight – easy and done, right?
Unfortunately, that theory doesn’t work for many reasons. The theory that all calories have the same impact on your weight and metabolism remains one of the most persistent nutrition myths that keeps us fat and sick.
All calories are the same in a laboratory when you burn them in a vacuum. However, your body is not a laboratory. It is an intricate, interconnected organism that simultaneously juggles thousands of duties.
Food controls everything. Food affects the expression of your genes that cause or prevent disease. In other words, food literally turns on health genes or disease genes. It tells those genes to store or burn fat. Food influences your hormones, your brain chemistry, your immune system and even your gut flora.
Let’s look at just one example of how our society places importance on the number of calories, not the quality. Newer public policies require restaurants to list calorie contents next to menu items. This becomes an example of completely misguided policies about helping people make better food choices. Calories from a Cinnabon, for example, are different than calories from an avocado in how they affect your hormones, your metabolism and even your appetite. Sadly, mainstream thinking has not caught up.
This is not some hypothetical idea. Food affects your metabolism at every level. It works fast in real time with every single bite. That ultimately becomes very empowering: You can change your health starting with your very next meal!
Eating Fat Helps You Burn MORE Calories
Kevin Hall, from the National Institutes of Health, studies mathematical systems and biology. He found when you measure every ounce of food, every movement, every breath and every calorie burned, you find that those who ate more fat compared to an identical amount of carbs burned over 100 more calories a day . Over a year, that amounts to about a 10-pound weight loss from doing no more exercise.
Hall also reported studies on brain imaging and brain function that found eating more fat actually shuts off your brain’s hunger and craving centers. Eating healthy fats improves things like food intake, taste preferences and even your metabolism.
Dietary fat – again, higher in calories per gram than carbs or protein – can positively impact the whole calorie-burning process. It’s a mind bender, right?
I have long pondered what really causes weight gain for most people. If I asked random people on the street, they would likely reply overeating or eating too much fat makes us gain weight. Sounds like a reasonable assumption right?
Yet in a brilliant paper published in the Journal of the American Medical Association (JAMA), Harvard professor Dr. David Ludwig lays out the case for a very different view of obesity and metabolism .
Ludwig argues we don’t get fat from eating more and exercising less. Instead, it’s the reverse – being fat makes you eat more and exercise less. Essentially your fat cells get hungry and drive you to overeat.
How We Gain Weight: Hungry Fat Cells
Here’s how this plays out in your biology.
The first domino to fall is when sugar – and remember, all processed carbs including wheat bread turn to sugar – spikes your fat-storing hormone insulin .
You don’t even have to be overweight at that point. Insulin then drives all available fuel in your bloodstream into your fat cells, especially those around your middle that we call visceral fat, organ fat or most commonly, belly fat. This stimulates your brain to make you eat more.
The second thing is when you try to restrict calories and exercise more – the typical solution to lose weight – your body becomes alarmed, fearing you’re starving. That makes you tired, so you move less to conserve energy. It makes you hungry, so you eat more.
Evolutionarily, this makes sense: Until you find food, your metabolism slows down so you don’t die. That was important at one point in human history; however, it’s clearly not a problem today because we live in a food carnival.
Attempts at weight loss that follow the “eat-less, exercise-more” formula ultimately fail most people. Sure, it can work for a little bit, but you will almost always rebound and gain the weight back.
In fact, less than 10 percent of people who lose weight can keep it off for a year. You can walk around hungry and tired for a bit, but not for long. By not eating enough food, you place your body into a starvation mode.
Here’s where it gets interesting. You can also starve your body by eating the wrong foods; namely, too much sugar and refined carbs. When you eat a lot of sugar and carbs, your body thinks it’s starving.
Sounds a bit counterintuitive, right? How can your body act like it’s starving when there’s plenty of calories and food around?
Well, when you eat sugar, refined carbs or anything that raises your blood sugar, it causes a spike in your fat storage hormone – insulin. Then, a vicious cycle that includes hunger, cravings and overeating ensues.
Speed Up Your Metabolism with a High Fat Diet
In human experiments, those who ate high-fat diets had a much faster metabolism . Low-fat, high-carb diets spiked insulin, subsequently slowing their metabolism and storing belly fat. The higher-fat diet group had a faster metabolism, even eating the same amount of calories.
Another human study, also conducted by Dr. Ludwig and his Harvard colleagues, compared high-fat, low-carb diets with high-carb, low-fat diets in a controlled feeding study  (where researchers provided all the food). Again, the high-fat group did better.
These same researchers subsequently did something called a crossover trial, where you use the same study subjects to test different diets. For half the study, they ate one way; for the second half, they ate the opposite diet. So half the group ate high-fat, low-carb and half ate low-fat, high-carb; then they flipped those diets for the second part of the study.
This type of study allows researchers to study the effects on metabolism for different diets on the same person, creating a more accurate, comprehensive picture about the most effective eating plan.
While their macronutrient ratios differed, both groups ate the exact same number of calories for each diet.
What happened was shocking. The high-fat group ended up burning 300 more calories a day than the low-fat group. The high-fat group also had the most improvements in cholesterol, including lower triglycerides, lower LDL, and lower levels of PIA-1 (that shows a less likelihood of having blood clots or inflammation ). They also showed bigger improvements with insulin resistance  or pre-diabetes .
The take-home here is that most of your fat-cell biology becomes controlled by the quality and type of the food you eat. That explains why we should eat a quality fat , whole-food diet that’s lower in refined carbohydrates, low-glycemic and high in fiber. That plan would include healthy fats like avocados, coconut oil, olive oil, nuts and seeds, and eggs.
If you have increased the amount of quality dietary fats in your diet, how has that affected your health and how you feel? I love avocado and coconut butter: What are YOUR favorite healthy fats? Share yours below or on my Facebook page .
Wishing you health & happiness,
Mark Hyman, M.D.