Received May 15; Accepted Aug 9. This article has been cited by other articles in PMC. Abstract Background Reported associations between preparing and eating home cooked food, and both diet and health, are inconsistent. Most previous research has focused on preparing, rather than eating, home cooked food; used small, non-population based samples; and studied markers of nutrient intake, rather than overall diet quality or health.
We aimed to assess whether frequency of consuming home cooked meals was cross-sectionally associated with diet quality and cardio-metabolic health. Participants self-reported frequency of consuming home cooked main meals. Diet quality was assessed using the Mediterranean Diet Score, Dietary Approaches to Stop Hypertension DASH score, fruit and vegetable intake calculated from a item food frequency questionnaire, and plasma vitamin C.
Markers of cardio-metabolic health were researcher-measured body mass index BMI , percentage body fat, haemoglobin A1c HbA1c , cholesterol and hypertension. Differences across the three exposure categories were assessed using linear regression diet variables and logistic regression health variables.
Results Eating home cooked meals more frequently was associated with greater adherence to DASH and Mediterranean diets, greater fruit and vegetable intakes and higher plasma vitamin C, in adjusted models. Those eating home cooked meals more than five times, compared with less than three times per week, consumed More frequent consumption of home cooked meals was associated with greater likelihood of having normal range BMI and normal percentage body fat.
Associations with HbA1c, cholesterol and hypertension were not significant in adjusted models. Conclusions In a large population-based cohort study, eating home cooked meals more frequently was associated with better dietary quality and lower adiposity. Further prospective research is required to identify whether consumption of home cooked meals has causal effects on diet and health.
Electronic supplementary material The online version of this article doi: Home cooking, Diet, Cardio-metabolic health Background The prevalence of obesity and diet-related non-communicable diseases NCDs , such as type II diabetes, hypertension, and certain cancers, have been increasing steadily worldwide [ 1 ]. These changes have been accompanied by a decrease in the time spent cooking at home in the majority of developed countries [ 2 , 3 ].
Concern has been expressed by policy makers, practitioners and researchers in the field of food and nutrition regarding a perceived decline in cooking skills, which has been hypothesised to be linked to the increase in diet-related NCDs [ 4 — 6 ]. Certain studies, primarily cross-sectional in design, have indicated that a higher frequency of cooking and preparing food at home may be associated with consuming a healthier diet [ 7 — 9 ] and benefits to health and longevity [ 10 — 12 ].
In contrast, other cross-sectional research has suggested that home food preparation and cooking may be associated with diets lower in fibre and higher in fat, saturated fat, sugar, and salt [ 13 , 14 ] and could potentially be detrimental to health [ 15 , 16 ].
Adding to this confusion, the majority of research to date has used cooking and food preparation practices as an exposure, rather than the consumption of home cooked food itself. Since eating food is more proximal to potential diet and health outcomes, focusing on behaviour upstream may be more likely to introduce confounding, for example regarding gender — given that more women than men engage in food preparation [ 3 ], and women tend to have healthier diets [ 17 ].
Of key primary interest therefore is establishing whether consuming home cooked meals is associated with benefits to diet and health, and subsequently investigating who eats home cooked meals, and then who prepares these meals and why.
To date, research investigating the potential advantages and disadvantages for diet and health of cooking and preparing food at home has generally focused on specific dietary indicators, rather than overall diet quality or health, and assessed measures cross-sectionally or after a brief follow-up period [ 18 ].
Despite the fact that the evidence base for relationships between cooking and both diet and NCDs is mixed and inconclusive, the promotion of home cooking forms part of public health strategies to improve diets and reduce obesity and diet-related NCDs internationally [ 21 ]. Further research is therefore crucial, to investigate on a large scale the potential associations between consumption of home cooked meals and diet and health outcomes. In this study we aimed to assess whether the consumption frequency of home cooked meals was cross-sectionally associated with indicators of diet and cardio-metabolic status.
In view of the current evidence base, we hypothesised that eating home cooked meals more frequently would be associated with markers of a healthier diet and improved cardio-metabolic health. Methods Data source The Fenland Study is a population-based cohort study investigating interactions between genetic and lifestyle factors in determining obesity and diabetes.
The study recruited adults born between and from general practice lists in Cambridgeshire, United Kingdom UK , between and [ 22 ]. Participants were invited to attend one of three clinical sites in Cambridgeshire to take part in a detailed assessment.
The data collection tools are available online [ 23 ]. Study exclusion criteria included previously diagnosed diabetes, psychosis, terminal illness, pregnancy, and inability to walk unaided. All participants provided written informed consent to participate in the study. Frequency of consumption of home cooked meals Exposure was derived from an item in the participant questionnaire: The first two response categories were collapsed to yield appropriate numbers for statistical analysis, as previously [ 24 ], giving a three category variable: Participants completed a item, semi-quantitative food frequency questionnaire FFQ for their food intake over the previous year [ 27 ], which has been shown to yield valid and reproducible food intake assessments, and has been validated previously in dietary data collection in the European Prospective Investigation into Cancer and Nutrition EPIC studies [ 28 ].
Total daily intake was provided in grams for carbohydrate, fibre, fat, saturated fat, sugar, protein, fruit, vegetables and alcohol. Total daily sodium intake was measured in milligrams, and total daily energy intake in kilojoules. Dietary intake values were winsorized at 1st and 99th percentiles, by replacing the smallest and largest percentage values in the distribution with the observations closest to them [ 30 ].
This was undertaken to account for their positively skewed distribution, and the limitations of the FFQ as a tool to collect precise data on dietary intake [ 31 , 32 ].
Data on dietary supplements were not collected. The consumption of a more DASH accordant diet is associated with positive health indicators and lowered cardio-metabolic risk [ 33 — 35 ]. The DASH diet assumes that beneficial impact is derived from the overall diet, rather than individual foods or nutrients playing important roles [ 36 ].
This index includes eight components one nutrient and seven food groups based on eating guidance from the United States US National Heart, Lung and Blood Institute [ 37 ]. Scoring is established through quintile rankings, on the basis of relative comparisons to the rest of the sample, with men and women classified separately.
Participants are allocated a score from one lowest quintile to five highest quintile for energy-adjusted intake of: In contrast, for intakes of red and processed meat; sodium; and sugar-sweetened beverages, participants are allocated a score from one highest quintile to five lowest quintile. Scores are then combined to give a total DASH score, ranging from a minimum of eight to a maximum of 40 points.
The Mediterranean diet is generally considered to be low in consumption of red meats, moderate in consumption of fish, poultry, fermented dairy products and wine, and high in consumption of fruits, legumes, cereals and olive oil [ 38 , 39 ]. Concordance with the Mediterranean diet has been linked with positive health outcomes, in particular the primary prevention of cardiovascular disease [ 40 ]. Scores of zero, one or two were allocated for each of nine dietary components, including legumes; fruit and nuts; vegetables; ratio of monounsaturated and polyunsaturated fatty acids to saturated fatty acids; fish; meat products; dairy products; cereals; and alcohol [ 25 ].
This also aimed to help reduce measurement errors, since energy intake is partially associated with over-reporting and under-reporting of dietary intake [ 41 ]. MDS scores were then standardised using the z-score. Markers of cardio-metabolic health We used body mass index BMI , percentage body fat, haemoglobin A1c HbA1c , cholesterol and hypertension as indicators of cardio-metabolic health.
Elevated total cholesterol and low levels of high density lipoprotein cholesterol HDL are associated with increased risk of cardiovascular disease [ 46 ], and the derived ratio of total cholesterol to HDL is used in the QRISK2 model to estimate risk of cardiovascular disease over the next ten years [ 47 ].
In line with UK guidance, a ratio of 4. Height and weight were measured at the clinical sites by trained observers, with participants wearing light clothing and barefoot. Height was measured to the nearest 0. Weight was measured to the nearest 0. BMI was derived as weight kg divided by height m2. Dual-energy X-ray absorptiometry DEXA; Lunar prodigy advanced fan beam scanner GE Healthcare was used to assess body composition, and has been described in detail elsewhere [ 22 ].
A three-compartment model fat mass, fat-free mass and bone mineral mass was used to estimate percentage total body fat. Hypertension is associated with an elevated risk of developing cardiovascular disease [ 53 ]. Using an upper arm cuff and automated oscillometric device, three sets of diastolic and systolic blood pressure measurements were performed on each participant.
The first readings were discarded and the lowest systolic and lowest diastolic readings from the last two readings were used for assessment. Participants currently taking hypotensive medication, or self-reporting a diagnosis of hypertension from a clinician, were also classified as hypertensive.
Participants were asked whether or not they had been employed in the past four weeks, and those answering yes were identified as currently working. Socioeconomic status was assessed using age at leaving full time education, which was divided into three categories: Physical activity was measured objectively using an integrated movement and heart rate sensor Actiheart; CamNtech, Cambridge, UK attached to the chest via two standard ECG electrodes and worn during free-living over six days [ 56 ].
A ramped treadmill protocol test was used to individually calibrate heart rate, as undertaken previously [ 57 ]. Periods of non-wear were inferred from the combination of non-physiological heart rate and prolonged periods of inactivity, which were taken into account to minimise diurnal information bias when summarising the intensity time-series.
Data were processed [ 58 ] and a branched equation framework [ 59 ] used for modelling to estimate intensity time series. Statistical analysis All analyses were on a complete case basis. The outcome variable with the greatest missingness was vitamin C missing for participants and the covariate with the greatest missingness was physical activity missing for participants.
Differences in the characteristics of Fenland study participants included and excluded from the analytic sample were tested using the Mann—Whitney test for continuous variables and Pearson Chi squared test for categorical variables.
Differences in covariates and markers of diet and cardio-metabolic health across the three frequency categories of consuming home cooked meals were assessed using descriptive statistics Kruskal-Wallis test and Pearson Chi squared test. Separate analyses were then run for each outcome variable, using linear regression for continuous diet variables and logistic regression for binary health variables.
Analyses were adjusted for covariates: The analyses for markers of cardio-metabolic status were additionally adjusted for dietary variables MDS, DASH score, plasma vitamin C, fruit and vegetable intakes to assess the potential health benefits of consuming home cooked meals independent of dietary improvements. All analyses were conducted using Stata version 14; Stata Corp. Results Participant distribution is summarised in Additional file 2. A slight majority of the included sample was female Most participants were non-smoking There were significant differences between the included and excluded participants in terms of sex, age, smoking status, physical activity expenditure, working status, and frequency of consuming home cooked meals.
Participants who ate home cooked meals more frequently tended to be female, older, non-smokers, not currently in work, working fewer hours and not working overtime, older at leaving full time education, with greater daily alcohol intake. Participants who consumed home cooked meals more frequently generally had higher plasma vitamin C, higher fruit and vegetable intakes, and higher MDS and DASH score.
They were also less likely to have an overweight BMI, excess percentage body fat, high risk cholesterol ratio, or to be at risk of developing diabetes according to HbA1c level. Table 1 Characteristics of participants overall and by frequency of consuming home cooked meals Covariatea Consumption of home cooked main meals Total.