By Elizabeth Goodman Artis for Shape.com
Fat is the ultimate three-letter word, especially the kind that you spend so much time watching your diet and hitting the gym to keep at bay (or at least to keep off your butt). But beyond making you look less-than-svelte, fat can have significant physical and emotional implications. We talked to Shawn Talbott, Ph.D., a nutritional biochemist and author of The Secret Of Vigor: How To Overcome Burnout, Restore Biochemical Balance, And Reclaim Your Natural Energy, to find out a few essential facts that might surprise you.
Fat Comes In Different Colors
More specifically, there are different types of fat that have different hues and functions, according to Talbott: white, brown and beige. The white fat is what most people think of as fat -- pale and useless. Useless in that it has a low metabolic rate so it doesn't help you burn any calories the way muscle does, and it's the predominant type of fat in the human body, encompassing more than 90 percent of it. In other words, it's a storage unit for extra calories.
Brown fat is darker in color due to a rich blood supply and can actually burn calories rather than storing them -- but only if you're a rat (or other mammal); certain critters can activate brown fat to burn calories and generate heat to keep them warm in winter. Humans, sadly, have so little brown fat that it won't help you burn calories or keep you warm.
The third type of fat, beige fat, is in between white and brown in terms of its calorie-burning ability, which is actually very exciting. Why? Because researchers are looking into ways to shift white fat cells into more metabolically active beige ones via diet and exercise or supplements. In fact, there is preliminary evidence that certain hormones which are activated by exercise may convert white fat cells into beige ones, as well as some evidence that certain foods such as brown seaweed, licorice root and hot peppers may have the ability to do this as well.
The Fat On Your Butt Is Healthier Than The Fat On Your Belly
It's probably safe to say that no woman favors the fat on one body part over another, but it's actually safer health-wise to be more of a pear than an apple, Talbott says. Belly fat, also known as visceral fat, is much more responsive to the stress hormone cortisol compared to the fat on your thighs or butt, so when stress hits hard (and you don't find a healthy way to handle it), any extra calories consumed are more likely to end up around your middle.
Belly fat is also much more inflammatory than fat located elsewhere in the body and can create its own inflammatory chemicals (as a tumor would). These chemicals travel to the brain and make you hungry and tired, so you're more likely to overeat or eat junk food and not exercise, thus creating a vicious cycle and perpetuating the storage of more belly fat. The good news is that anything that helps you reduce inflammation helps reduce those signals to the brain. Talbott recommends fish oil (for the Omega 3's) and probiotics, which you can take in pill form or get by eating yogurt with active cultures.
First You Burn Calories, Second You Burn Fat
The term "fat-burning" is thrown around willy-nilly in fitness circles, but as an expression of weight loss, it's indirect. Before you "burn" fat, you burn calories, whether those calories come from stored carbohydrates (glycogen and blood sugar) or from stored body fat. The more calories you burn during each workout, the bigger deficit you will create and the more fat you will lose.
You can also create a calorie deficit by eating less. The trick, though, is time, since it's hard for most people to put in the time needed to burn enough calories to make a weight-loss dent. Talbott (and many other experts) advocates high-intensity interval training (HIIT) to burn as many calories as possible in as short amount of time as possible. This method, which alternates between hard/easy efforts, can burn double the calories in the same amount of time spent exercising in a steady state.
Fat Affects Your Mood
Certainly there is no easier way to ruin your day than seeing you've gone up a few numbers on the scale, but having excess fat -- especially around your belly -- activates that inflammation/cortisol cycle, which studies show may be a factor in serious mood disorders like bipolar disorder. If you're stuck in a stress/eat/gain/stress cycle, however, you're likely to experience at least a perpetually low mood, even if you don't have an actual clinical condition.
To help break the cycle, try eating a square of dark chocolate, suggests Talbott; there is just enough sugar to satisfy a stress-induced craving, but the healthy flavonoids help calm inflammation that leads to more stress. Low-fat dairy products like yogurt can have a similar effect -- the combination of calcium and magnesium can help calm the stress response.
Even Skinny People Can Have Cellulite
The dreaded c-word is caused by fat trapped under the skin (known as subcutaneous fat). The overlying skin "dimples" are created by connective tissues that tie the skin to the underlying muscle, with fat trapped in between like a sandwich. You don't need a lot of fat to cause a dimpling effect, so you can be in great shape and have low body fat but still have a little pocket of dimpled fat, for example, on your butt or the backs of your thighs.
Building muscle while losing fat (and the fat loss part is key -- you have to have it to lose) can help minimize the appearance of cellulite; cellulite-specific creams and lotions can also help minimize the look of dimpled skin (though they can't do anything about the trapped fat beneath).