Dr. Ntambi is interested in how genetic factors interact with diet, hormones, and other environmental factors to impact obesity, heart disease, and diabetes.

Dr. Ntambi received his bachelor’s and master’s degrees at Makerere University in Kampala, Uganda. He earned his Ph.D. at Johns Hopkins University in Baltimore. Since 2002, he has been teaching a semester-long course for undergraduates about economics and health in Uganda, followed by a three-week trip to Uganda. This trip led to the creation in 2006 of the Village Health Project, which works in a village called Lweza to support agriculture/nutrition and clean water for the village.

The effects of fat in your diet is still a hotly debated topic in the field of nutrition. What is agreed on is that there are different kinds of fat, which are classified based on their structure. Fats contain long chains of carbon atoms, strung together, with chemical bonds in between. Each carbon can make a total of four bonds — so in a long string of single-bonded carbons, each carbon will have a “leftover” bond and attach to a hydrogen. If every carbon has a hydrogen, this is called a “saturated” fat, because it can’t break any bonds to add a new hydrogen.

However, if some of the carbons are double bonded to each other (C=C), then they don’t have any bonds left over for hydrogen. Since they could potentially break their double bond and grab a hydrogen, this is an “unsaturated” fat. Saturated fats also have different shape than unsaturated fats because the carbons attached by a double bond will be closer together than the carbons attached by a single bond, meaning that they won’t all be equally-spaced. This creates a “kink”, which is thought to be part of why unsaturated fats (with double bonds) are important in the body: the bends help keep cell membranes from getting too stiff.

Dr. Ntambi studies a protein called stearoyl-CoA desaturase (SCD). It’s a complicated sounding name, but its job is basically to create a double bond, turning a saturated fat (no double bonds) into a monounsaturated fat (one double bond). It has been shown in mice that if you turn up the expression of SCD, the mice will become obese, which supports the idea that too much unsaturated fat is unhealthy.

Dr. Ntambi has been working to show the effect from the opposite direction: he has genetically engineered mice to have no/low amounts of SCD and shown that those mice are much less likely to develop obesity or diabetes.