Being able to measure diets well is also important for\ntesting whether following dietary recommendations actually has the benefits to\nhealth envisaged by proponents of the ideal diet. <\/p>\n\n\n\n
So, how do we know what food patterns people are following? How do we know whether they are following dietary recommendations? Or, as the nutritional epidemiologists would put it, what is the quality <\/em>of people\u2019s diets?<\/p>\n\n\n\n A quick recap from my last post<\/a>:<\/strong> There is little agreement on what a healthy, ideal, diet should look like in detail, but eating (whole) food, not too much of it, and mostly fruits, vegetables, whole grains and legumes (i.e. plants) appears to represent most of the common ground. Governments, dieticians and others tell people how they should eat in a number of ways, the most visible of these being through food-based dietary guidelines (FBDGs). <\/p>\n\n\n\n In this post, I’ll outline how others are measuring alignment with ideal diets and whether these approaches could be adapted for my research project.<\/p>\n\n\n\n Starting in nutritional epidemiology (the study of the relationship between nutrition and health) around 20 years ago, the term \u2018diet quality\u2019 was introduced as researchers wanted to evaluate people\u2019s dietary habits, find out whether nutritional interventions were working and whether diet-related disease outcomes could be predicted (Alkerwi, 2014). In the same way that we cannot tie down a single \u2018ideal\u2019 diet, what makes a diet low or high quality is debated. Indeed, the field of nutritional epidemiology has itself been called into question because of its inability to provide the means to accurately measure diets (Satija et al., 2015). <\/p>\n\n\n\n While there is wide agreement that a high-quality diet should\nbe safe, hygienic and one that promotes optimal growth and development,\nprevents diseases and health hazards, diet quality is considered \u2018an open-textured\nnotion where no single static definition exists\u2019 (Alkerwi, 2014). Diet quality can\nbe used as an umbrella term for how well an individual or group\u2019s collective\ndiet conforms to dietary recommendations (Alkerwi, 2014), so its meaning and\nhow it is measured differs according to the objectives informing those dietary\nrecommendations. <\/p>\n\n\n\n There are two main approaches to characterising dietary\npatterns (describing how people eat): the first is \u2018bottom-up\u2019 and involves\nlooking at the available data on what people are eating, grouping the foods (or\nkey nutrients) eaten and defining the dietary pattern based on the quantity at\nwhich they are usually consumed; the second approach is \u2018top-down\u2019 and starts\nwith a set of criteria for adhering to dietary guidelines (e.g. FBDGs) which\nfood consumption data can be scored against and diets can be explained in\nrelation to (Kant, 2004). <\/p>\n\n\n\n This is how I think about the two approaches: <\/p>\n\n\n\n![\"\"](\"http:\/\/www.plantagbiosciences.org\/people\/anna-whitton\/wp-content\/uploads\/sites\/87\/2019\/05\/20190503_125742-3-1024x768.jpg\")
My first (delicious, and I reckon pretty healthy) lunch at CIAT, Cali. <\/figcaption><\/figure><\/div>\n\n\n\nThe diet quality concept<\/strong><\/h3>\n\n\n\n
![\"\"](\"http:\/\/www.plantagbiosciences.org\/people\/anna-whitton\/wp-content\/uploads\/sites\/87\/2019\/05\/09NUTRITION-articleLarge-1.jpg\")
Step 1: Defining dietary patterns <\/h4>\n\n\n\n
![\"\"](\"http:\/\/www.plantagbiosciences.org\/people\/anna-whitton\/wp-content\/uploads\/sites\/87\/2019\/05\/Blog-2-graphics-DP-approaches-2-1024x315.jpg\")
![\"\"](\"http:\/\/www.plantagbiosciences.org\/people\/anna-whitton\/wp-content\/uploads\/sites\/87\/2019\/05\/20190505_175604-1-e1557196624477-768x1024.jpg\")
![\"\"](\"https:\/\/www.plantagbiosciences.org\/people\/anna-whitton\/wp-content\/uploads\/sites\/87\/2019\/05\/DQIs.png\")