After cooking over a hot stove for a few hours, stewing tomatoes or sautéing onions and garlic, do you ever find that despite the delicious aromas wafting through the house you just aren't very hungry at dinnertime? You're probably thinking it's because you need a break after working so hard, and that may be the case, but is it possible that the smells curbed your appetite, acting as a natural suppressant?
That's the theory Alan Hirsch, MD, is employing in his latest weight loss research at the Smell and Taste Treatment and Research Foundation in Chicago. He is developing flavor crystals to intensify the flavors in foods, which may make people eat less.
The idea started when Hirsh noticed that patients often gained weight immediately after losing their ability to smell. Hirsch wondered if the opposite might be true -- if intensifying scents and taste could lead to weight loss and a decreased appetite.
Smell and taste are closely linked, Hirsch tells WebMD. In fact, he says 90% of what people consider taste is really smell. If you find that hard to swallow, try holding your nose shut while eating something -- what people do on the television show Fear Factor when asked to eat things like worms and roaches -- and you'll find it difficult to taste the flavors in foods.
"It made some anatomical sense," Hirsch says, because of a connection between the nose and the brain. The reason people feel full, he says, is because it's usually our brains, not our stomachs, that interpret whether we've had enough food. This is based on how much food enters our mouth, as well as how much we smell and taste.
But don't delicious scents provoke hunger, at least initially? When Hirsch gave candy bars to medical students, for example, he told them to sniff the bars 10 times when hungry and then put the bars back in their desks. The whiffs of chocolate didn't suffice, and at the end of the day there weren't any candy bars left.
That's why he developed odors contained in plastic tubes that can't be ingested. After studying more than 3,100 dieters, he found that people using the tubes lost an average of 30 pounds in six months, while the traditional dieters lost only 6 pounds.
Hirsch can't say why exactly the odor tubes worked. Originally he thought that the aromas made you feel fuller faster by tricking the brain. Now he's not so sure.
"It may have nothing to do with that at all. It may have just acted as a displacement mechanism, so instead of grabbing the doughnut you grab the inhaler," he says. Also, aroma might help satisfy cravings, or the sniffing might remind people on diets not to eat.
Regardless of how it works, the idea of sniffing a tube all day isn't very practical, which is why Hirsch shifted his attention to developing crystals that people can sprinkle on foods before eating. Hirsch says people don't even notice a difference in the way their foods taste when using the crystals, which range in flavor from cheddar cheese and horseradish to mocha and strawberry -- there are 12 in all.
And the Survey Says ...
Findings from a large study of the flavor crystals -- Hirsch is hoping to enroll 9,000 participants -- won't be available for several years, but preliminary findings are somewhat promising. Over six months, crystal users lost an average of about 35 pounds overall, while traditional dieters had an average weight gain of about one pound. The study was small, however, involving only about 110 people.
Still, some experts question whether the crystals can really be effective over time.
"Obesity is now the second leading cause of preventable deaths in the U.S.," says Fred Pescatore, MD, author of The Hamptons Diet. "That's never going to go away if we continue to look for tricks or gimmicks to help people lose weight."
Most people would agree that you need to take a well-rounded approach to weight loss and shouldn't rely on something like flavor crystals alone to reach your goals. "Any tricks that work for people are important, but to predicate an entire dieting program on sprinkling your foods with crystals is difficult to buy into." Instead, he says, exercise and healthy eating are the best ways to lose and maintain weight -- facts most dieters just don't want to hear.
Even if the crystals can decrease appetite, or trick the brain into thinking we're full, there is no guarantee that they will stop people from eating more. In a culture where food is either supersized or measured out into tiny quantities, eating amounts based on how hungry we feel or what our bodies tell us is a foreign idea to most people.
"Appetite probably plays the least role in gaining weight," says Pescatore, who is based in New York City. Most people, he says, eat because of psychological reasons including depression. "Focusing on those reasons is the real key. People need to figure out why they're eating, because then they will be better at controlling it."
One of the reasons people eat excessively, however, may include sensory factors. "There is probably a percentage of the population eating for the sensory tactile things about food, just like how some people eat for comfort," says Susan Mitchell, PhD, RD, a nutritionist in Orlando, Fla. "Someone may have a lot of emotional issues, and their outward way of dealing with that emotion is through food. For others, it might be the taste and smell that drives them, but they don't realize how much they are eating."
Even Hirsch says the crystals might not work for everyone. "This may only work for people eating for the sensory component," he says.
Putting Your Senses to Work
The findings of this study won't be completed or published for several years. In the meantime, experiment at home by better using your sense of smell and taste while eating. "Sniff your food before you eat it," says Hirsch. "Chew slowly, and take your time." Try enjoying more spicy or savory foods -- not a difficult task for most dieters, who often eat the same foods day after day.
But why stop at smell and taste alone? Instead, try using all of your senses and really enjoy foods, which may bring greater satisfaction. Mitchell recommends adding lots of fruits and vegetables to your diet, which in addition to being colorful and flavorful, have lots of natural health benefits. Most of all, eat for the nutrition and the pleasure, says Mitchell. "I think we've gotten away from both." If you take your time and use all of your senses, you just might find that some of your cravings are satisfied before your fork hits the plate.