Avoid carbohydrate-rich food in the evening if the sugar metabolism is disturbed
People with prediabetes should avoid carbohydrate-rich foods such as pizza or pasta in the evening. Because with them, starchy and sugary foods have a negative effect on blood sugar regulation, as German researchers have now found out.
Late eating with unpleasant consequences
Since late meals are supposed to make you fat, some people use the method of not eating after 6 p.m. to reduce their weight. Meals that are particularly high in carbohydrates should be avoided in the evening anyway, especially by people with impaired glucose tolerance. Because this increases their blood sugar, as researchers now found.
Negative effects on blood sugar regulation
A nutritional study led by the German Institute for Nutritional Research (DIfE) has shown that the so-called internal clock also influences how people with a sugar metabolism disorder react to carbohydrate-rich food.
As the DIfE and the German Center for Diabetes Research (DZD) report, the evening consumption of foods rich in starches and sugars in men with prediabetes (pre-stage of diabetes) had a negative effect on blood sugar regulation.
"In comparison, the timing of carbohydrate intake did not play a major role in blood sugar regulation in healthy study participants," the report says.
According to the information, only men participated in the study, since the examination of circadian rhythms in women is considerably more difficult due to the menstrual cycle. The study results were published in the scientific reports.
The internal clock plays a role
It has long been known that the so-called internal clock plays a role in the regulation of metabolic processes and that sugar metabolism is also subject to a certain daily rhythm.
In addition, recent studies on rodents indicate that the internal clock also influences how the metabolism reacts to the intake of carbohydrates or fats and that certain time slots are more suitable from a health perspective than others for eating a carbohydrate-rich or high-fat diet.
Observational studies in humans also concluded that people who eat high carbohydrates in the morning but are low in fat have a reduced risk of type 2 diabetes or the metabolic syndrome.
The latter is characterized by symptoms such as excessive fat storage in the abdomen, high blood pressure and a disturbed sugar and fat metabolism.
However, the exact interplay between the diet and the daily rhythmic regulation of sugar metabolism has not been sufficiently researched.
Study participants with sugar metabolism disorder
In order to find out more about the physiological mechanisms underlying this interaction, the scientists at DIfE carried out a nutritional study on a total of 29 men who were on average around 46 years old and had an average body mass index of 27, which is normal - until you were very overweight.
A sugar metabolism disorder was found in 11 of the subjects at the start of the study. So they already had fasting blood sugar levels or their blood sugar levels dropped significantly more slowly than normal after a sugar exposure test.
By contrast, the blood sugar regulation was not disturbed in the remaining study participants; their glucose tolerance was normal.
Diet rich in fat and carbohydrates
During the study, subjects had to follow two different diets for four weeks each, both of which provided the same amount of calories, carbohydrates, fats and protein.
However, they differed at what time of day the participants mainly consumed carbohydrates or fats.
Diet plan A stipulated that the participants should eat carbohydrates from 1:30 p.m. and from 4:30 p.m. to 10:00 p.m. According to diet plan B, they ate high-fat foods in the morning and carbohydrate-rich foods in the afternoon and evening.
No effect on healthy men
"As our study shows, it is relevant at least for men with a sugar metabolism disorder at what time of day they consume a carbohydrate-rich meal," explained first author Katharina Kessler.
"If we compared the blood sugar values measured after the two diets, their blood sugar levels after diet B were on average 7.9 percent higher than after diet A, in which the participants ate fat in the evening," the scientist continued.
“Interestingly, we could not observe this effect in healthy men, although we generally noticed a decrease in glucose tolerance over the course of the day in both healthy and preloaded people. However, the latter was much stronger. "
Avoid carbohydrate meals in the evening
The researchers also observed a change in the secretion of the intestinal hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) in the preloaded men, which contribute to the regulation of sugar metabolism and body weight and the release of which is subject to a certain daily rhythm.
For example, in parallel with the markedly pronounced, afternoon decrease in glucose tolerance, the blood levels of the two hormones decreased significantly more than in healthy study participants.
“The circadian rhythm of hormone release therefore influences how we react to carbohydrates,” says endocrinologist Andreas F. H. Pfeiffer, who heads the Clinical Nutrition department at DIfE.
For this reason, diabetologist Natalia Rudovich and scientist Olga Pivovarova from DIfE recommend that people who already have a sugar metabolism disorder should follow their internal clocks and avoid carbohydrate-rich meals in the evening. (ad)