Investigating the Healthiness of Internet-Sourced Recipes

Implications for Meal Planning and Recommender SystemsDr. Christoph Trattner Department of New Media Technology

Context

Trattner, C. and Elsweiler, D. Investigating the Healthiness of Internet-Sourced Recipes: Implications for Meal Planning and Recommender Systems. In Proc. WWW’17.

@ctrattner @delsweil

Why is research on (online) food useful?

Food is one the main concepts that shapes how good we feel and how healthy we are.

According to the WHO, within the last three decades overweight and obesity in the EU population rised dramatically > 30% (especially for the younger generation

Resulting in a cost of approx. € 81 billion a year to help people with chronic diseases

…A government’s response to increasing incidence of lifestyle-related illnesses, such as obesity, has been to

encourage people to cook for themselves…

Cooking inspiration:

Questions RQ1: How healthy are Internet-Sourced recipes with

respect to recognized standards? RQ2: How do user interactions such as ratings, comments

or social bookmarks people apply to recipes relate to the healthiness of recipe content?

RQ3: How healthy are the recipes recommended by standard recommendation algorithms when applied to the food recommendation problem?

RQ4: Can we improve standard recommender algorithms in terms of making the recommendations they offer more healthy?

Question?

Dataset

Nutrition Facts

Basic statistics:

60,983 recipes 125,762 users rating 155,769 users bookmarking 1,032,226 ratings 17,190,534 bookmarks

Dataset: Allrecipes.com

Allrecipes.com popularity

According to Alexa.com

Questions RQ1: How healthy are Internet-Sourced recipes with

respect to recognized standards? RQ2: How do user interactions such as ratings, comments or

social bookmarks people apply to recipes relate to the healthiness of recipe content?

RQ3: How healthy are the recipes recommended by standard recommendation algorithms when applied to the food recommendation problem?

RQ4: Can we improve standard recommender algorithms in terms of making the recommendations they offer more healthy?

Question?

Determining the healthiness

FSA food health criteria

Usda. cook more often at home. available at http://www.choosemyplate.gov/weight-management-calories/weight-management/better-choices/cook-home.html. Last accessed on 20.6.2016. 2011.

WHO

food

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J. Who and F. E. Consultation. Diet, nutrition and the prevention of chronic diseases. World Health Organ TechRep Ser, 916(i-viii), 2003.

Determining the healthiness

Internet recipe healthiness

Internet recipes are quite unhealthy!

User perception

Results when asking users (n=32) how healthy categories are on Allrecipes.com

(Kappa κ = .165, z = 42, p < .001)

Internet recipesvs

TV chef recipesvs

Supermarket ready meals

Comparing recipes

Internet recipe health comparison

Trattner, C. Elsweiler, D. and Simon, H. Estimating the Healthiness of Internet Recipes: A Cross-Sectional Study. Frontiers in Public Health, 2017.

WHO

crite

riaFS

A cr

iteriaHealthiness over time

There is not much change over time!

Questions RQ1: How healthy are Internet-Sourced recipes with respect

to recognized standards? RQ2: How do user interactions such as ratings, comments

or social bookmarks people apply to recipes relate to the healthiness of recipe content?

RQ3: How healthy are the recipes recommended by standard recommendation algorithms when applied to the food recommendation problem?

RQ4: Can we improve standard recommender algorithms in terms of making the recommendations they offer more healthy?

Question?

Spearman rank correlation,* p < .05, ** p < .01, *** p < .001

Results: Interaction Correlation

Questions RQ1: How healthy are Internet-Sourced recipes with respect

to recognized standards? RQ2: How do user interactions such as ratings, comments or

social bookmarks people apply to recipes relate to the healthiness of recipe content?

RQ3: How healthy are the recipes recommended by standard recommendation algorithms when applied to the food recommendation problem?

RQ4: Can we improve standard recommender algorithms in terms of making the recommendations they offer more healthy?

Question?

*** p < .001

Results: Recommender

Libray: LibRecEval: 10 fold-cross validation

∆=𝑡𝑟𝑎𝑖𝑛−𝑝𝑟𝑒𝑑

Std. recommender produce unhealthy

suggestions!

Questions RQ1: How healthy are Internet-Sourced recipes with respect

to recognized standards? RQ2: How do user interactions such as ratings, comments or

social bookmarks people apply to recipes relate to the healthiness of recipe content?

RQ3: How healthy are the recipes recommended by standard recommendation algorithms when applied to the food recommendation problem?

RQ4: Can we improve standard recommender algorithms in terms of making the recommendations they offer more healthy?

Question?

Pearson correlations (= rho) between MAP and nDCG and FSA and WHO health scores (on user level) for individual algorithms.

Sign. high correlation

Correlation

Post-Filter scoring functions

Linear combinations as discussed in Elsweiler et al. (2015) did not work

Re-ranking for health

D. Elsweiler, M. Harvey, B. Ludwig, and A. Said. Bringing the "healthy" into food recommenders. In Proc. ofDRMS’15., pages 33–36.

Results: Recommender (2)

Note: similar results with bookmarks

Std. recommender can be enhanced

to produce healthy suggestions!

OK, that’s it!

for now ;)

Take home:

Internet-sourced recipes are not per

se healthy