Meal timings are important modifiable factor in type 2 diabetes risk, study confirms

7th August 2023

Eating breakfast after 9am increases the risk of developing type 2 diabetes by 59 per cent compared to people who eat breakfast before 8am, according to a new study.

Researchers from the Barcelona Institute for Global Health (ISGlobal) found that modifying the time at which people eat can reduce the risk of developing type 2 diabetes.

Eating breakfast before 8am and dinner before 10pm and eating more frequently throughout the day were associated with a lower incidence of type 2 diabetes.

The findings are published in the International Journal of Epidemiology and suggest meal timings are an important modifiable factor in managing the incidence of type 2 diabetes.

Type 2 diabetes incidence

The researchers analysed data from 103,312 participants who were part of the French NutriNet-Santé cohort between 2009 and 2021. Each participant recorded what they ate and drank over a 24-hour period on three non-consecutive days for an average of 5.7 days in the first two years of the study.

The researchers then assessed the participant’s health for an average of seven years and looked at the association between meal frequency and timing, the duration of night-time fasting between meals and the incidence of type 2 diabetes.

During the study, there were 963 new cases of type 2 diabetes, and the researchers found that the time at which food was eaten impacts the risk of developing diabetes.

Incidence of type 2 diabetes was higher in the participants who ate their breakfast after 9am compared to those who ate an early breakfast before 8am. Participants who ate an early breakfast and those who ate regularly throughout the day had a lower incidence of type 2 diabetes.

The researchers found no link between fasting and the incidence of type 2 diabetes and found that prolonged fasting was only beneficial if it included having an early breakfast before 8am and an early dinner.

Meals and glucose control

Dr Anna Palomar-Cros, a researcher from ISGlobal and first author of the study, said: ‘We know that meal timing plays a key role in regulating circadian rhythms and glucose and lipid control, but few studies have investigated the relationship between meal timing or fasting and type 2 diabetes.

‘Biologically, this makes sense, as skipping breakfast is known to affect glucose and lipid control, as well as insulin levels.’

The researchers suggest that a first meal before 8am and a last meal before 7pm may help reduce the incidence of type 2 diabetes.

Some 4.3 million people in the UK live with type 2 diabetes, and estimates from Diabetes UK suggest that 2.4 million more people are at high risk of developing the disease. Type 2 diabetes is associated with several modifiable risk factors, including obesity and overweight and smoking.

A version of this story was originally published by our sister publication Nursing in Practice.

Regularly eating breakfast and fibre associated with a lower overall mortality risk

9th September 2021

Regularly eating both breakfast and fibre appears to be associated with a significantly reduced risk of overall and cardiovascular mortality.

It is often said that breakfast (BF) is the most important meal of the day and there are numerous studies indicating the positive health benefits among those who eat BF. For example, some evidence suggests that not eating breakfast is associated with an increased risk of heart disease, a 21% higher risk of developing type 2 diabetes and a greater risk of all-cause mortality. Nevertheless, while these data are relatively consistent, less is known about which BF foods are potentially associated with a lower incidence and risk of cardiovascular events. One dietary component that is present in common BF foods such as oatmeal, fruit and cereals, is fibre. Furthermore, a recent umbrella review of prospective observational studies concluded that higher fibre intake appears to positively impact on not only cardiovascular disease but overall mortality.

These data led a team from the Department of Family Medicine, West Virginia University School of Medicine, West Virginia, US, to confirm the association between BF, dietary fibre and mortality. The team used the National Health and Nutrition Examination Survey (NHANES) dataset and included individuals aged 40 years and over who self-reported on dietary intake between 1999 and 2002. To determine survival information, the team used a 2015 database which provided mortality follow-up details from the NHANES study. Using the NHANES data, the researchers included those who self-reported as BF eaters and based on the foods eaten, categorised dietary fibre intake as high (> 25 g/day) and low (< 25 g/day). Since hypertension, diabetes and cardiovascular disease can negatively impact on mortality, the analysis included these three factors as covariates. The primary outcomes of the study were all-cause and cardiovascular disease (CVD) mortality and the team included a cohort of non-breakfast eaters which served as a control group.

Findings
A total of 5761 individuals were identified, 4778 BF eaters with a mean age of 57.5 years (46.6% male) and the remainder, a matched cohort of non-breakfast eaters. The average calorie intake was higher in breakfast eaters compared to non-breakfast eaters (2041.1 vs 1871.1, p = 0.001). Furthermore, dietary fibre intake was also higher among BF eaters (16.9g vs 12.8 g, p < 0.0001). During the follow-up period of approximately 147.6 months, there were 2027 (35.2%) all-cause deaths and 469 (8.1%) CVD deaths. After adjustment for covariates, breakfast eaters had a reduced risk of all-cause mortality (adjusted Hazard ratio, aHR = 0.45, 95% CI 0.32 – 0.63) and CVD mortality (aHR = 0.79). Among BF eaters with a fibre intake > 25g/day, there was a 21% reduction in all-cause mortality (aHR = 0.79, 95% CI 0.66 – 0.96) compared to non-breakfast eaters. While there was a trend towards lower CVD mortality among breakfast eaters with fibre intakes > 25g/day, this was not significant (aHR = 0.82, 95% CI 0.50 – 1.35, p = 0.42). Among non-breakfast eaters, there were no significant associations between fibre intake and either all-cause or CVD mortality.
The authors concluded that the mortality benefit from eating breakfast observed in both their own and earlier studies appears to be linked with higher intake of fibre.

Citation
King DE et al. A Relationship Between Mortality and Eating Breakfast and Fiber. J Am Board Fam Med 2021