A recent study conducted in Sweden has found that older adults who typically go longer without eating may develop chronic diseases faster than those with shorter gaps between meals. The study, which followed nearly 3,000 people aged 60 and over, discovered that those who usually went longest without eating developed chronic diseases faster than those who had shorter gaps between meals. This difference was most pronounced among individuals aged 78 and over.
The study used data from a long-running Swedish study of ageing, which began between 2001 and 2004. Participants, who were 74 years old on average, reported their usual times for eating meals, snacks, and drinking. Researchers calculated the longest gap between any two times participants ate or drank during a typical 24-hour day, providing a measure of their usual fasting time. The analysis took several factors into account, including diet quality, smoking, sleep, education, living arrangements, social connections, and care needs.
Participants were divided into four groups based on how long they typically went without eating each day. The shortest-fasting group went between six and 11.5 hours, while those in the longest-fasting group habitually did so for between 14 and 24 hours. Researchers found that people who went 14 to 24 hours without eating developed chronic diseases faster than those with shorter fasting periods. This included cardiovascular diseases, such as heart failure and stroke, and neuropsychiatric conditions, such as depression and dementia.
However, the study found that long gaps between meals made no difference for musculoskeletal conditions like arthritis and osteoporosis. Age appeared to play a significant role, with participants aged 78 and over experiencing faster accumulation of chronic diseases when fasting for longer periods. In contrast, no clear association was found among those aged 60 to 77.
Several biological processes may explain why fasting has different effects at different ages. The digestive system can become less efficient in later life, reducing the absorption of essential nutrients. Longer fasting periods compress the time available for eating, potentially making it harder for older people to obtain and absorb enough nutrients. Muscles also respond less effectively to protein with age, and eating protein regularly throughout the day provides repeated signals that help the body maintain muscle.
Medication use may also be an important factor, as some medicines need to be taken with food to improve absorption or reduce side-effects, while others can affect blood sugar if taken far from meals. Although the study took frailty and difficulties with everyday activities into account, it was unable to determine whether long fasting periods caused people to develop diseases faster or if poor health led to longer fasting periods.
The study's findings suggest that fasting advice may need to account for age, nutritional vulnerability, medication use, and existing health problems. An eating pattern that offers some metabolic benefit earlier in adulthood may carry additional risks later in life, when getting enough nutrients, maintaining muscle, and staying physically independent can become harder. The results may not be generalizable to other countries, rural or disadvantaged communities, and among older people living in institutions.
Key points
- Long gaps between meals may have negative effects on older adults, particularly those aged 78 and over.
- The study found an association between longer fasting periods and faster development of chronic diseases, including cardiovascular diseases and neuropsychiatric conditions.
- Fasting advice may need to account for age, nutritional vulnerability, medication use, and existing health problems.
