Why do products with a reduced sugar content lift the mood?

Recently, more and more attention has been paid to the influence of nutrition on our mental health, the cause-and-effect relationships of nutrient intake and their reflection on the psychological and physical state of man are being investigated, and it is noticed that food choices, including sugar content and glycemic index, play a key role in building emotional and energy balance.

The glycemic index (GI) is a numerical scale that measures how quickly blood glucose levels rise after eating food. Glucose, which comes mostly from carbohydrates, is the main source of energy for cells, and an increase in its level after a meal stimulates the secretion of insulin from the pancreas. Foods with a high GI raise glucose levels more quickly, causing sudden spikes and drops in blood sugar, which will lead to fatigue and irritability. In contrast, low GI foods raise glucose levels more slowly, maintaining more stable energy levels and insulin balance, and reducing the risk of sudden mood swings.

A 2016 study(1) looked at how carbohydrates, including glycemic load, affect mood in healthy adults. In a study of 82 participants, a high glycemic load diet was associated with 38% higher depressive symptom scores, 55% higher total emotional instability scores, and 26% higher fatigue scores compared to a low glycemic load diet. Obese participants had 40% higher scores on the depression scale compared to people of normal body weight.

These results emphasize the importance of dietary decisions for mental health, especially in the obese, and for the prevention of chronic diseases and metabolic syndrome. It is recommended to limit the intake of white sugar and flour, to choose foods rich in fiber, to consume proteins from fish, lean meat and dairy products, and to give priority to quality fats.

(1) Breymeyer KL, Lampe JW, McGregor BA, Neuhouser ML. Subjective mood and energy levels of healthy weight and overweight/obese healthy adults on high- and low-glycemic load experimental diets. Appetite. 2016 Dec 1;107:253-259. doi: 10.1016/j.appet.2016.08.008. Epub 2016 Aug 6. PMID: 27507131; PMCID: PMC5154680.