In a review of research on the effect of meal patterns on health, the few studies available suggest that eating irregularly is linked to a higher risk of metabolic syndrome (high blood pressure, type 2 diabetes and obesity). The limited evidence highlights the need for larger scale studies to better understand the impact of chrono-nutrition on public health, argue the authors of two new papers, particularly with the rise in shift workers and ‘social jetlag’ where many of us live by social clocks rather than our internal body clocks.
Our current lifestyle has become demanding and more irregular. Food consumption patterns have changed markedly over the past decades: more meals are skipped, consumed outside the family home, on-the-go, later in the day, and more irregularly. Two papers published in the Proceedings of the Nutrition Society explore the implications for health from different eating habits, reviewing the evidence from a number of dietary studies as well as global differences in eating habits.
Eating inconsistently may affect our internal body clock or ‘circadian rhythms’ which typically follow a 24-hour cycle. Many nutritionally related metabolic processes in the body follow a circadian pattern such as appetite, digestion and the metabolism of fat, cholesterol and glucose. Food intake can influence our internal clocks, particularly in organs such as the liver and intestine, whilst our central clock is also regulated by the dark/light cycle which in turn can affect food intake. Chrono-nutrition involves studying the impact of nutrition on metabolic processes and how these may be influenced by and also alter circadian patterns through nutrient intake (ir)regularity, frequency and clock time.
A number of studies have shown that people working shifts have an increased risk of a number of diseases including cancer, cardiovascular disease and metabolic syndrome. For shift work, changes in dietary patterns are therefore an important aspect to consider when investigating its effects on health.
Social jetlag is estimated to affect more than 80% of the general population in central Europe, especially people living in urban areas. This discrepancy between our internal body clock and social clock has been linked to a greater risk of diseases like obesity and metabolic syndrome, whilst shorter periods of sleep have been linked to weight gain.