Fat is simply excess calories stored as unsightly blubber that should be removed at all costs. Right? Wrong. Scientists are learning that fat is actually critical to the health of our bodies. That's because fat not only stores calories, but it produces hormones that our bodies need to function. By way of these hormones, fat can influence our appetite, metabolism, bone strength, reproductive organs, immune system, and even our brain size. It's no wonder that nature wants to maintain fat—it’s important! And because it’s important, fat is endowed with many ways to protect itself. Some of them are explained below:
1. Fat loss increases our appetite.
Fat produces a hormone called leptin, which travels through our bloodstream and reaches our brain, where it affects our appetite. Normally, we are satiated. We get hungry around mealtimes, but nothing out of the ordinary. However, when we lose fat, we lose leptin (fat produces leptin, so less fat means less leptin). When this happens, our brains react by making us extremely hungry. Studies show that people who have lost 10 percent or more of their body weight are more preoccupied with food, have bigger responses to images of food, and are less able to control their intake. Fat is vital, and your body and mind want you to put it back on!
2. Fat loss lowers metabolism.
Again, when we lose fat, we lose leptin. Leptin produced by fat also allows muscles to function optimally. With less leptin, our muscles become more efficient and reduce our metabolism by about 10 percent at rest and 25 percent during exercise. Between the stronger drive to eat described in No. 1 and the slowing metabolism, is it any surprise that we regain weight so easily?
3. Fat can divert blood supply to itself.
It sounds like science fiction, but it’s true! As we gain fat, it sends a signal to our veins that causes new capillaries to sprout in the direction of fat. These vessels become a supply of nutrients, oxygen, and waste removal that our fat needs to sustain itself. They also create a new channel by which extra calories can be stored and turned into—you guessed it—fat!
4. Fat can be created without any food at all.
Stem cells are the multipotent cells in our bodies that can create various tissues depending on the body’s needs. As our bones, muscle, or cartilage wear out, our body uses stem cells to replace them. And fat is on this special VIP list! When our bodies are in need of new fat cells, stem cells will preferentially turn into fat over bone or muscle cells. For example, the bone marrow of patients with anorexia nervosa is often populated with numerous fat cells as their body goes into overdrive trying to replace lost fat.
5. It's not only sloth and gluttony that make us fat.
Though overeating and inactivity will certainly help us pack on the pounds, fat has many other ways of growing. Hormones play a role in weight gain, and our fat-burning hormones—such as growth hormone and testosterone—decrease as we age. As that happens, we gain weight even though we may be eating the same amount as we did before. Gut bacteria have a role in producing fat too, as some bacteria are more efficient at extracting calories from our food than others. Scientists have also found genes that predispose certain people to obesity. And finally: gender. Women store fat at two to three times the rate that men do and have a more difficult time losing it, too. That's probably no surprise to any woman reading this article!
So if you’re having trouble losing fat thanks to yo-yo dieting, age, or genetics, what can you do? Don’t despair. Although nature loves to hold on to our fat, once we're educated, we have the power to fight back. Here are some tips:
- Restrict eating to an eight-hour interval. Research shows that limiting calorie intake to a shorter time window helps reduce fat and decreases appetite—even if someone is eating as many calories as they did when they ate throughout the whole day.
- Exercise to support the metabolism. Exercise helps counter a slowing metabolism caused by weight loss, and a combination of strength training and aerobic exercise for just one hour three times per week improves metabolism. Studies show that even people who had liposuction on their abdomen or thighs regain the weight in their bellies after the procedure unless they increased their exercise!
- Be careful not to overexercise. Hitting the gym too often can also cause a hunger spike. Add activities slowly as your body gets used to higher levels of exertion.
- Use hormones to your advantage. Levels of key fat-busting hormones decrease with age, but exercise and intermittent fasting will increase them. In addition, long bouts of aerobic exercise (over two hours) have been shown to increase growth hormone, and strength-building exercises such as squats or leg presses have been shown to increase levels of both growth hormone and testosterone. Not eating at night is also useful, as growth hormone levels peak at night, and eating reduces its effect.
With your newfound knowledge about fat, you can outsmart its many self-preservation mechanisms in your body.