Effects of regular breakfast habits on metabolic and cardiovascular diseases: A protocol for systematic review and meta-analysis

BACKGROUND: Breakfast, which is considered as an important meal of the day, is being ignored by an increasing number of people as the pace of modern life accelerates. Although a large number of previous studies have reported the relationship between skipping breakfast and type 2 diabetes mellitus, most of them were cross-sectional studies. It remains unclear how skipping breakfast affects such specific cardio-metabolic diseases as hypertension, strokes and hypercholesterolemia. METHODS: The protocols and reports of this meta-analysis are based on a meta-analysis of observational studies in epidemiological guidelines (MOOSE). Relevant studies were systematically retrieved from PubMed, Embase, Web of Science and the Cochrane Library, and were restricted to English from the inception to May 10, 2019. All the results were obtained by RRs, and outcomes of interests should include the occurrence of cardiovascular and metabolic diseases. RESULTS: Fourteen cohort studies in total were eventually included. Compared with people having breakfast frequency(≦3times/week), those with a frequency(>3 times/week) have reduced the risk of type 2 diabetes mellitus, obesity, Metabolic Syndrome, Low high-density lipoprotein cholesterolemia, Cardiovascular Diseases, cardiovascular Mortality, hypertension and strokes, with (RR = 0.8 [95% CI: 0.7–0.91], P = .142, I(2) = 37.6%), (RR = 0.74 [95% CI: 0.59–0.94], P < .001, I(2) = 89%), (RR = 0.86 [95% CI:0.75–0.99], P = .512, I(2) = 0%), (RR = 0.75 [95% CI:0.61–0.93], P = .643, I(2) = 0%), (RR = 0.87 [95% CI:0.81–0.93], P = .479, I(2) = 0%), (RR = 0.63 [95% CI:0.51–0.78], P = .396, I(2) = 0%), (RR = 0.92 [95% CI:0.86–0.98], P = .419, I(2) = 0.7%), and (RR = 0.89 [95% CI:0.79–0.99], P = .238, I(2) = 29%), respectively. CONCLUSIONS: A regular daily breakfast habit benefits the cardio-metabolism to a great extent, reducing the risk of Cardiovascular Diseases, type 2 diabetes mellitus, obesity, hypertension, strokes, Metabolic Syndrome, cardiovascular Mortality, Low high-density lipoprotein cholesterolemia, and Abdominal obesity, while it is not significantly related to hypercholesterolemia and coronary heart disease regardless of gender. Nevertheless, skipping breakfast once a week may greatly reduce the benefits of cardio-metabolism. Therefore, public institutions should promote and encourage citizens to cultivate regular daily breakfast habits.