Eating More Home-Cooked Meals Associated with Lower Risk of Weight Gain, Type 2 Diabetes

Analysis of 2 large health worker cohorts suggests that people can reduce their risk of developing diabetes by preparing more of their meals at home.

Investigators followed 58,051 initially healthy women from 1986 to 2012 and 41,676 initially healthy men from 1986 to 2010.

Over the course of 2.1 million person-years of follow-up, 9,356 of the subjects developed type 2 diabetes mellitus (T2DM). After adjustments for various demographic, behavioral and socioeconomic factors, analysis showed that the hazard ratio (HR) for incident T2DM fell steadily as the consumption of homemade meals increased.

The HR of incident T2DM among patients who ate 0-6 homemade meals per week was defined as 1. That rate fell to 0.93 (95% confidence interval [CI], 0.88-0.99) among those who ate 7-8 homemade meals per week, 0.96 (95% CI, 0-90-1.03) among those who ate 9-10 homemade meals per week and 0.86 (95% CI, 0.81-0.91) for those eating 11-14 homemade meals per week (p for trend < 0.001).

When investigators separated the effect of eating homemade lunches and homemade dinners, the latter appeared to be more important. Patients who ate 5-7 homemade lunches per week had a 9% lower risk of developing diabetes as those who ate 0-2 homemade lunches per week (p<0.001). Patients who ate 5-7 homemade dinners per week had a 15% lower risk of developing diabetes as those who ate 0-2 homemade dinners per week.

“One possible reason is the higher contribution of evening meals to total energy and nutrient intake for Americans,” the study authors wrote in PLOS Medicine. “Over the past four decades, daily energy from lunch was typically between 23.3% and 26.8% among US adults, and the range for dinner was 36.2%—38.8%, which may lead to a greater health impact of dinner than lunch.”

The investigators concluded that people who ate out frequently were more likely than others to develop diabetes, at least in part, because they gained more weight over the course of the study period. In the first 8 years of follow-up, women who consumed 11-14 homemade meals per week had 0.34 kg (95% CI, 0.15—0.53) less weight gain than those with 0–6 homemade meals.

Men who consumed 11-14 homemade meals had and 1.23 kg (95% CI, 0.92—1.54) less weight gain than those who ate 0-6 homemade meals. Among participants who started off non-obese (body mass index [BMI] < 30 kg/m²), those who ate 10-14 homemade meals per week were 14% less likely to become obese (95% CI, 0.82—0.91; p-trend < 0.001) than those who at 0-6 homemade meals per week.

Again, consuming homemade dinners appeared to be more important than consuming homemade lunches. People who ate 5-7 homemade dinners per week were 24% less likely to become obese 95% CI, 0.70-0.83; p-trend < 0.001) than those who ate 0-2 homemade dinners per week.

Although the authors of the new paper believe theirs is the first to find that homemade meals reduce the risk of incident T2DM, they say their findings are in line with a large number of earlier studies that have found that eating out increases diabetes risk.

“Similarly, previous studies focusing on MPOH (meals prepared outside the home) demonstrated that frequent consumption of foods in sit-down and fast-food restaurants was associated with excess weight gain as a result of prolonged positive energy balance,” they wrote. “For instance, each serving/week of fast-food consumption at baseline was associated with 0.32—0.74 kg more weight gain over 15 years in the CARDIA study.”