Many frustrated dieters have shared the experience of virtuously intending to eat just one chip, or one spoon of ice cream — only to find ourselves unable to stop eating until we’ve reached the bottom of the container.  We beat ourselves up afterwards, bemoaning our lack of willpower — but science suggests another culprit may share the blame: Palmitic acid. Found abundantly in meat and whole milk dairy products, this saturated fat is also present in palm oil, used extensively in shelf stable junk foods (e.g., cookies, chips, pastries); see chart below for palmitic acid sources. We’ve long known it can clog your arteries — but new research suggests it may also hijack your brain!

Researchers at the University of Cincinnati compared the neurochemical and metabolic impact of different kinds of fats in a mouse study.  Usually, when fat is ingested there is a rise in blood levels of leptin, a hormone that controls appetite and also triggers thermogenesis, the conversion of calories to body heat. Compared to healthy, monounsaturated fats like those found in olive oil, palmitic acid interfered with this process dramatically — the leptin still circulated in the bloodstream, but palmitic acid reduced the normal brain response to the hormone by roughly half.  In practical terms, this may help explain why it’s so easy to overeat foods like steaks, burgers, ice cream and chips — to the detriment of your figure and your health.

Food   Palmitic Acid
Butter, unsalted (1 Tbsp.)  3,038 mg
Margarine containing palm oil (1 Tbsp.)  1,180 mg
Cheddar cheese (1 oz.)  2,745 mg
Vanilla ice cream (1 cup) 4,038 mg
Donut, glazed (one large)  2,873 mg
Coconut meat (one cup shredded)  2,839 mg
 Potato chips (1 oz.)  2,609 mg
 Boston cream pie (1 slice)  1,164 mg

By contrast, a plant based diet not only fills you up physically, fruit and vegetables contain compounds that help support the right hormonal balance needed for hunger control.  For example, Japanese researchers have identified phytochemicals in strawberries, blackberries, blueberries and blood oranges that increased production of leptin in animal trials. Other research found that dieters who ate a cup of raisins a day for six weeks enjoyed a 38% increase in leptin levels. Instead of ice cream, try the Yonanas machine — a gadget we found that takes your frozen bananas and quickly turns them into a rich, creamy dessert. Not only will you avoid brain-sabotaging palmitic acid, you’ll get the Dole Banana Diet benefit of resistant starch, which helps support fat metabolism.

 Published July 1, 2011