Feeling Full

Tomorrow is Thanksgiving and the temptation to over-eat is tremendous! (For those who are new to my blog and want to know more about turkey you can read last year's post here.) So I thought that the topic of satiety signals would be apropos. But first, how many of us are aware of the difference between hunger and appetite? Hunger is physiological, appetite is psychological. Many of us, probably me included, will continue to eat because of appetite, not hunger tomorrow. We will completely ignore our bodies and keep right on eating well past being full.

Satiety is the condition of being full, or at least of feeling full so that your know when to stop eating. In your body satiety is a set of physiological signals that come from your gastrointestinal tract to your brain; specifically the brain stem and hypothalamus by way of the vagus nerve. The hypothalamus is our body's regulator of food behavior - it tells us to keep eating or to stop eating. (We know that this occurs here because people who have injured their hypothalamus have difficulty regulating their eating behaviors.) But other things are occurring when we eat; hormones are produced (somewhere around 20-30, including insulin) which may also be telling the brain when you are full.

New research is suggesting that a naturally occurring family of fats derived from lecithin, called oleoylethanoamide or OEA, play a role in signaling satiety; OEA appears to "talk" to the vagus nerve inducing satiety and reducing food intake. OEA is a combination of oleic acid (omega-9 like is found in olive oil) and ethanolamine. Although studies are currently ongoing, and are being done on rats not people, some interesting findings are being reported. In addition to appetite suppression, OEA appears to encourage fatty acid catabolism and lower blood lipid levels.

Because many of the foods we eat at Thanksgiving are high in fat and sugar, and low in protein (well, excluding the turkey) and fiber we don't feel satiated for very long. Keep this in mind as you munch your way through the meal tomorrow and listen for your satiety signals!