My editor recently forwarded a press release to me about a product called Spray Thin, a "fresh new way to reduce the desire to overeat and help people lose weight."
Imagine losing weight by simply spraying your meals and snacks with scents specifically designed to curb appetite and, according to results of the company-sponsored study, you could lose as many as 33 pounds in six months.
It sounded sketchy to me. Before dismissing this as another "too good to be true" product for effortless weight loss, I decided to look into it further. It turns out, there is a scientific basis for using smell to aid in weight loss.
Scientists already know the area of the brain that processes information about smell is linked to brain centres that control appetite . It's also well established that age-related loss of smell can cause poor appetite, malnutrition and weight loss in the elderly.
It seems a keen sense of smell can help regulate the amount of food you eat. Researchers recently demonstrated that certain aromas released during chewing and swallowing foods activate regions in the brain that control satiety.
By accelerating satiety, odour molecules in food could help people stop eating sooner. The evidence is flimsy, however, whether this results in weight loss.
In 1995, Dr. Alan R. Hirsch of the Smell and Taste Research Foundation in Chicago published a study on so-called smell therapy and weight loss. He asked 3,193 overweight volunteers to inhale various sweet aromas three times in each nostril whenever they felt hungry over six months. The findings: the more often participants used the scent inhalers, the more pounds they lost.
Those who scored well on a smell test – ate two to four meals a day and felt bad about overeating – lost nearly five pounds a month. Individuals who had poor smell test scores – and tended to snack more than fives times a day – didn't lose weight. These findings are interesting but don't prove cause and effect. There was no control group to compare with and important variables, such as exercise, weren't measured.
Similar research done at the Human Neuro-Sensory Laboratory in Washington revealed that among 80 overweight subjects motivated to lose weight, those who inhaled specifically formulated scents lost 19 pounds over four months. The control group who inhaled placebo scents lost, on average, four pounds. Sounds promising, but information about lifestyle wasn't collected. It's possible that people given the special aromas consumed fewer calories each day and/or exercised more than those in the placebo group.
If certain scents can calm your appetite, others can rev it up (think bread baking in the oven, burgers on the grill). According to a small study from the U.K., overweight participants had a much keener sense of smell than their thinner counterparts, particularly after they had eaten.
It's unclear what this actually means, but researchers speculate that a higher sense of smell may play a more active role in triggering food intake among heavier people.
Spray Thin isn't the only product promising to naturally suppress your appetite. Sensa Sprinkles, Aroma Patch and Appetite Control Scent Inhalers are other products that use scents to sell the promise of weight loss.
My attempt to learn more about Spray Thin and the data backing the product proved futile. Two weeks after receiving the press release, the company's website was gone and the 1-800 number was out of service. It seems Spray Thin was too good to be true.
Special scents promising to reduce appetite are not a magic bullet to weight loss. Successfully losing weight requires making long-term changes to diet and exercise habits.
That said, savouring your foods – and the aromas they release when chewed – might help dampen your appetite. Before buying a product, practice the following tips to help curb your appetite.
Savour the aroma. Before eating a meal, take a moment to smell the foods on your plate. Eating mindfully without distractions (watching television, reading, checking e-mails) allows you to concentrate on the foods you're eating.
Choose hot over cold. Hot or warm foods release more aroma than cold foods, which can help satisfy your appetite.
Go for more flavour. Foods with stronger aromas are more flavourful and tend to be more filling. Add garlic, herbs and spices to meals.
Chew versus drink. Solid foods require chewing which allows more time for aroma molecules to activate your brain's satiety centre.
If protein shakes or smoothies are your go-to breakfast or snack, add a solid food to the mix. Perhaps a banana or green apple? Or consider adding a dash of vanilla or fresh mint leaves to your shake.
Slow your pace. To prolong the time hunger-suppressing aromas have to take effect, eat slowly. After every bite, put down your knife and fork and chew thoroughly. Don't pick up your utensils until you've swallowed your food.
Leslie Beck, a Registered Dietitian, is based at the Medisys clinic in Toronto. She can be seen every Thursday at noon on CTV News Channel's Direct.