Why are there people who are always hungry? And why are there those who, overweight or obese, are unable to follow a diet and are always struggling to lose weight? The answer seems to be in an excessive glycemic drop after the meal, as emerges from a very recent scientific research published in the prestigious journal Nature Metabolism by an American and English team from the Universities of Harvard Medical School, Leeds, Nottingham and King's College London ( Wyatt et al, Nature Metabolism, 2021).
The link between blood sugar and hunger, the experiment
One of the largest studies dedicated to nutrition and its effects on the body is currently underway. The name of this study is PREDICT and has provided researchers with the necessary data to understand the link between blood sugar and hunger. Scientists analyzed the lifestyle and health status of 1070 people. All the participants were asked to have the same breakfast, a muffin, while the other meals were free but chosen from a list of preparations provided. Two special devices, always worn by the volunteers for two weeks, the duration of the experiment, made it possible to continuously detect blood sugar and the activities carried out during the day, such as moving, eating or sleeping.
An excessive drop in blood glucose can be the problem
Analyzing the data it emerged that some people, after the blood sugar spike following a meal, had a significant and quick drop in blood sugar in the next two to four hours below baseline, before going back up. Well, it was observed that those who had this excessive drop in blood sugar also had 9% more hunger than those who did not have such a drop. Not only that, these people waited also around half an hour less, on average, before their next meal and consumed more calories, about 300 more in a day, than little dippers. According to the researchers, these factors can potentially lead to a weight gain of nearly 9 pounds in a year.
So, the drop in blood sugar after the peak that normally follows a meal is an indicator of how hunger that person may develop over the next few hours. Excessive drops can lead to hunger, more frequent meals, and more calories. This condition does not seem to be linked to age, gender or body mass index but rather to the metabolism of individuals. And this explains why, with the same diet, the answers in terms of body weight can be different. Therefore, to avoid these excessive drops in blood sugar, it can be useful to choose foods that provide slow-release sugars, such as wholefoods, bread, pasta and biscuits, and fruits and vegetables rich in fiber, in order to slow down the absorption of sugars and to reduce the blood sugar peak and the subsequent blood sugar drop.