Does a healthy diet have the same effect on your body as it does on your dining companion? A new study out of Israel suggests that there may be significant differences in the way we digest a specific food, thus throwing a monkey wrench into the debate about which approach is the healthiest diet.
Glycemic index not a fixed number
The Israeli study included 800 healthy and pre-diabetic participants who were between the ages of 18 and 70. After initial assessments including blood tests, body measurements and lifestyle choices, participants were asked to record their meals, physical activity and sleep. They also wore monitors that measured their blood sugar levels.
The researchers looked at the glycemic index (GI) of the foods that were eaten. This index, which is a measure of how a specific food affects blood sugar levels, was believed to be a fixed rate. This index was believed to be important because blood sugar is closely associated with diabetes and obesity. However, the Israeli analysis found that participants’ blood sugar levels actually varied greatly after eating a specific food. In fact, some individuals showed completely opposite responses in their blood sugar levels after eating the same food. For instance, some participants had blood sugar spikes when they ate a standardized meal of glucose while other participants only experienced this spike after eating white bread.
An individualized approach to ‘healthy’ foods
The researchers also found that participants metabolized seemingly “healthy” foods differently. For instance, one obese and pre-diabetic participant was actually sabotaging herself by eating tomatoes because her blood sugar levels spiked after eating this fruit.
"For this person, an individualized tailored diet would not have included tomatoes but may have included other ingredients that many of us would not consider healthy, but are in fact healthy for her," said Dr. Eran Elinav, who works in Weizmann Institute of Science’s Department of Immunology. "Before this study was conducted, there is no way that anyone could have provided her with such personalized recommendations, which may substantially impact the progression of her pre-diabetes."
So what does that mean for the everyday person? The future of dieting may quickly move to an individualized approach instead of the current one-diet-fits-all stance. Therefore, trendy diets—whether Atkins or Paleo—may work well for some people, but probably are not the best option for everyone. Study leader Dr. Eran Segal of the Weizmann Institute of Science’s Department of Computer Science and Applied Math said, “The huge differences that we found in the rise of blood sugar levels among different people who consumed identical meals highlights why personalized eating choices are more likely to help people stay healthy than universal dietary advice.”
Primary Sources for This Sharepost:
Cha, A.E. (2015). This Diet Study Upends Everything We Thought We Knew About ‘Healthy’ Food. The Washington Post.
Israeli21c. (2015). Diet Study Overturns All We Know About Healthy Eating.
ScienceDaily.com. (2015). ‘Healthy’ Foods Differ By Individual.
Zeevi, D., et al. (2015). Personalized Nutrition by Prediction of Glycemic Responses. Cell.