Do you ever wonder why some diets work for some people, but fail for others? Some believe that all diets work when you stick to them. However, a new study published in the journal Cell demonstrates how personalized nutrition and certain foods could either help or hamper a person’s health goals.
Israeli researchers tracked the blood sugar levels of 800 people for over a week. The results suggested that even if every participant consumed the same meals, the food metabolism process differed for each individual.
The metabolism of proteins, fats, and carbohydrates will indirectly or directly lead to the production of blood sugar. If blood sugar becomes too high it can lead to certain health problems like diabetes and obesity. The glycemic index (GI) is a tool used to measure the effects of carbohydrates on a person’s blood sugar levels. Doctors and nutritionists will use the GI to help develop diets for clients and patients.
The researchers found that the GI of any given food is not a firm value. Instead, it depends on the person. For the study, researchers collected data through body measurements, health questionnaires, stool samples, blood sugar monitoring, blood tests, and a mobile-app that reported on an individual’s lifestyle habits and food intake. In total, 46,898 meals were measured. The study participants also received identical meals for breakfasts.
“Measuring such as large cohort without any prejudice really enlightened us on how inaccurate we all were about one of the most basic concepts of our existence, which is what we eat and how we integrate nutrition into our daily lives,” said study author Eran Elinav, of the Weizmann Institute of Science in Israel.
“In contrast to our current practices, tailoring diets to the individual may allow us to utilize nutrition as means of controlling elevated blood sugar levels and its associated medical conditions,” added Elinav.
Body mass index (BMI) and age were major factors linked with blood sugar levels after eating. On the other hand, the data revealed that the same foods consumed by different people had showed very different responses. At the same time, the person’s responses would not change on a daily basis.
Nutrition studies rely on the participants to follow a rigid diet and record their food intake honestly. The participants in the current study were asked to disrupt their routine by entering their meals into a food diary mobile app and eating a standard breakfast that included bread or sugar each morning. The researchers then provided a detailed analysis of each participant’s food responses. Strict compliance to the protocol was vital and meal reporting closely matched data from each participant’s blood sugar monitors.
The individualized feedback produced surprising results. For instance, one obese middle-aged woman with prediabetes found that eating tomatoes spiked her blood sugar levels. A tomato has a GI of less than 15 and is considered a low GI food, but for this particular woman tomatoes are not considered a healthy food.
To understand these reactions in different people, the researchers conducted bacteria analyses’ on stool samples collected from study participants. Gut bacteria is associated with diabetes, obesity and glucose intolerance.
The current study found that specific microbes correlated with blood sugar increases after a meal. The researchers were able to lower post-meal blood sugar levels and gut bacteria by conducting personalized diets in 26 additional study participants. What stood out to the researchers is that gut bacteria alterations were similar in all of the participants even though the diets were personalized and different.
“After seeing this data, I think about the possibility that maybe we’re really conceptually wrong in our thinking about the obesity and diabetes epidemic,” explained study author Eran Segal, also of the Weizmann Institute of Science in Israel. “The intuition of people is that we know how to treat these conditions, and it’s just that people are not listening and are eating out of control—but maybe people are actually compliant but in many cases we were giving them wrong advice.”
Sources for Today’s Article:
Zeevi, D., et al., “Personalized Nutrition by Prediction of Glycemic Responses,” Cell, 2015; 163(5): 1079, doi: 10.1016/j.cell.2015.11.001.
“’Healthy’ foods differ by individual,” ScienceDaily web site, November 19, 2015; http://www.sciencedaily.com/releases/2015/11/151119133230.htm.
Balch, J., et al., Prescription for Natural Cures: A Self-Care Guide for Treating Health Problems with Natural Remedies Including Diet, Nutrition, Supplements, and Other Holistic Methods (Hoboken: John Wiley & Sons, Inc., 2004), 197.