When blood sugar remains stable, it is easier to lose weight and prevent inflammation in the body. While it used to be assumed that there were "good" and "bad" foods, it is now known that postprandial blood sugar responses vary completely from person to person. Numerous factors are responsible for this, including a person's anthropometry, lifestyle, and the individual expression of the gut microbiome and human DNA. Glucose metabolism is a key factor in the development and progression of numerous diseases. Blood glucose spikes – followed by heavy insulin secretion – lead to weight gain and metabolic inflammation. A derailed blood-glucose metabolism can lead to obesity, type 2 diabetes mellitus and its sequelae, for example heart attack, stroke and various cancers. In addition, blood glucose fluctuations promote the development of numerous other diseases, including acne, psoriasis, atopic dermatitis, polycystic ovary syndrome, menopausal symptoms, atrial fibrillation, dementia and depressive disorder. Low blood glucose may induce an energy deficit in our brain and can lead to migraine. These disorders can be alleviated by stabilizing the blood glucose variation. For some of these diseases, no effective drug therapies are currently available. In others, a digital therapy can have a direct benefit or may reduce side-effects of drugs.