Meal planning, timing may affect CHD risk, related risk factors
Meal frequency and timing have an effect on CHD and related risk factors, according to a new American Heart Association scientific statement.
Marie-Pierre St-Onge, PhD, associate professor of nutritional medicine at Columbia University and chair of the group that wrote the statement, and colleagues provided a summary of the current scientific evidence on when and how often people eat and the effects of eating patterns on risk for MI, obesity, diabetes and other factors.
“Meal timing may affect health due to its impact on the body’s internal clock,” St-Onge said in a press release. “In animal studies, it appears that when animals receive food while in an inactive phase, such as when they are sleeping, their internal clocks are reset in a way that can alter nutrient metabolism, resulting in greater weight gain, insulin resistance and inflammation. However, more research would need to be done in humans before that could be stated as a fact.”
Skipping breakfast was associated with poorer cardiometabolic health across several studies.
According to one study, 74% of people who skipped breakfast did not meet two-thirds of the recommended dietary allowance for vitamins and minerals vs. 41% of those who ate breakfast. The study also showed that young adults who skipped breakfast were more likely to have a greater total energy intake from added sugars vs. those who ate breakfast.
Skipping breakfast also is associated with higher BMI globally, St-Onge and colleagues wrote. For example, a meta-analysis of 19 studies (n = 19,108) in the Asian and Pacific regions showed the group with the lowest frequency of breakfast consumption had greater prevalence of overweight or obesity vs. the group with the highest frequency of breakfast consumption (OR = 1.75; 95% CI, 1.57-1.95).
Studies also have shown that breakfast skipping is associated with impaired glucose metabolism, greater risk for diagnosed type 2 diabetes and higher risk for CHD and CVD, according to the researchers.
Individuals who ate breakfast daily were less likely to have elevated serum LDL, low serum HDL and elevated BP, St-Onge and colleagues wrote.
“On the basis of the combined epidemiological and clinical intervention data, daily breakfast consumption among U.S. adults may decrease the risk of adverse effects related to glucose and insulin metabolism,” the researchers wrote. “In addition, comprehensive dietary counseling that supports daily breakfast consumption may be helpful in promoting healthy dietary habits throughout the day.”
Meal timing and frequency
Studies also have shown that greater frequency of eating is associated with lower risk for obesity. In one study, participants who ate at least four times a day had an OR for obesity of 0.55 (95% CI, 0.33-0.91) vs. participants who ate three or fewer times per day, after adjustments for age, sex, physical activity and total energy intake.
Related studies also have shown that greater frequency of eating is associated with lower mean total cholesterol and LDL, according to the researchers.
Late-night eating has been associated with a greater risk for poor cardiometabolic health, St-Onge and colleagues wrote. For example, a Swedish study found that late-night eaters were more likely to be obese (OR = 1.62; 95% CI, 1.1-2.39) vs. non-late-night eaters.
“The impact of meal timing, particularly related to the evening meal, deserves further study,” the researchers wrote. “Epidemiological findings suggest a potential detrimental effect of late meals on cardiometabolic health, but clinical intervention studies, which would address causality, have been limited in scope and too diverse to draw definitive conclusions and make recommendations.”
Recommendations for further study
Because of the wide variation between definitions of meals and snacks across the studies, the researchers made recommendations to maintain consistency.
“On the basis of the current information, we propose that eating occasions be defined as any eating/drinking episode providing at least 210 kJ and that 15 minutes should be the minimum amount of time elapsed between separate occasions,” the researchers wrote. “Distinguishing between meals and snacks should be left to the participant’s discretion. This will provide a definition that accommodates different social norms and cultural behaviors.”
The researchers also made recommendations about what interventions may be beneficial.
“Although more direct translational research is still needed, these data suggest that intervening on meal timing and frequency may be beneficial,” the researchers wrote. “By focusing on meal frequency and timing as an intervention target, patients may directly address poor dietary quality without the need to deal with calorie restriction to promote weight loss.”
More data are needed to understand how intermittent fasting and eating speed may have an effect on weight and CHD risk factors, St-Onge and colleagues wrote. Additionally, special populations were underrepresented in the available data. The researchers recommended studies include considerations for racial/ethnic disparities in obesity and incidence of CVD, as well as children, adolescents and the elderly.
“We suggest eating mindfully, by paying attention to planning both what you eat and when you eat meals and snacks, to combat emotional eating,” St-Onge said in the release. “Many people find that emotions can trigger eating episodes when they are not hungry, which often leads to eating too many calories from foods that have low nutritional value.” – by Cassie Homer
Disclosure: St-Onge reports receiving grants from the NIH. Another researcher reports consulting for Nestle, speaking for the North American Menopause Society and the American Institute of Cancer Research and receiving research grants from the American Diabetes Association and the University of Illinois at Chicago.