How To Trick Your Brain Into Eating Less

Dieting is one of those things that most of us will have to do in our lifetime. And while there are many different diets out there to try, the old adage of “calories in, calories out” (i.e. don’t eat more than your body needs) plays a pretty big part in most of them. The early stages of a diet can therefore be especially difficult as we try to reduce the amount of food we eat. Many websites, books, and magazines will tell you there are ways to “trick” your brain into eating less, but will these tricks actually help you feel full while consuming fewer calories? I took a peruse through the recent literature, and tried to separate fact from fiction.

Claim: Eating slowly and with fewer distractions means you eat less

It was suggested in the 1970s that obese people eat at a faster rate, and that this in turn leads to weight gain. More recently, several studies have used this idea to treat both over- and under-eating with significant success. In 2009, Ford et al published data showing that training obese adolescents to eat slower reduced their BMI. This was accomplished using a piece of equipment called a Mandometer, which weighs food as it is being removed from a plate, calculates the rate of consumption, and then tells the subject to either speed up or slow down. More recent work from the same group has suggested that the feeling of satiety associated with eating slowly is a result of a balance of two gastrointestinal hormones, ghrelin and peptide tyrosine-tyrosine, that signal “fullness” to the brain. As for eating while distracted (for example with the TV on or while working at your computer), it seems likely that a similar effect is at play: The less attention you pay to your meal, the faster you eat.

Claim: Green tea and other natural supplements can help you lose weight

Many foods have been touted as having weight loss-promoting properties. Of these, perhaps the most promising is green tea. Made from the leaves and buds of Camelia sinensis, green tea is thought to elicit its effect on appetite because it contains polyphenols (a.k.a. catechins). Green tea has been suggested to function in a number of ways, but in a recent review of the literature, Navamayooran Thavanesan of the University of Oxford suggested that it is the combination of all of these effects that is important. Overall, polyphenols act on a number of cellular pathways to reduce fat metabolism and uptake. While green tea has clearly been shown to have an effect on weight loss, importantly most studies administer catechin capsules to subjects in order to normalize dose, and to have an effect that dose is equivalent to about SEVEN cups of green tea PER DAY!

Other edibles suggested to help you lose weight or feel fuller faster include cayenne pepper, coffee, almonds, and dark chocolate. The jury is out on whether these foods are active, however, so be wary of the articles claiming their effects.

Claim: Keeping a record of everything you eat reduces calorie consumption

Many dietitians recommend keeping a record of everything you eat as you try to lose weight, and there are even smart phone apps to track your every meal. But does this kind of documentation really help? According to a study published last year, yes. Scientists at University College London monitored weight loss in over 3,000 individuals using an Internet-based food monitoring service, and found that those who engaged fully with the website lost more weight than those who weren’t so conscientious. This effect seems to be a result of the fact that humans are generally goal-oriented, and thus tracking our progress when dieting keeps us motivated.

Claim: Eating breakfast reduces hunger while dieting and increases weight loss

Skipping breakfast has been suggested to result in weight gain due to increased hunger late in the day. Some even claim that eating breakfast “boosts your metabolism” in the morning. While some studies have shown that a protein-rich breakfast reduces appetite and therefore weight gain in adolescents, others suggest that the relationship between breakfast and weight loss is complex, and depends on the general behavior of an individual. For example, obese women who usually skipped breakfast saw increased weight loss when they incorporated the meal into their day, whereas those who already ate breakfast lost more weight if they started to skip. So should you eat breakfast or not? Probably, but this is one of those instances where one size does not fit all. Perhaps keeping a food diary would help you figure out what works for you.

Katie Pratt, Ph.D.

Katie recently received her Ph.D. in molecular biology at Brown University and is currently working as a freelance science writer, illustrator, and communicator, based in Providence, RI. She has been blogging for two years, both on her own website, KatiePhD.com, and around the science-web.