Chocolate: To Eat or Not To Eat?
Read the following research from Bohannon and Colleagues (2015) regarding chocolate consumption (1.5 oz per day) and weight loss. Answer the prompts as you read ;-)
Specifics of research:
1) What were the IV/s and DV/s?
IV: Type of diet (low carb + chocolate, low carb, & control)
DVs: weight, testing urine, mental state (well-being), and sleep patterns
Results:
2) Explain the data trends in the figure.
Figure shows average change in weight (kg) in chocolate group was the greater than carb group. Appears control group gained weight throughout the study.
Press Briefings were released and their work went viral, like big time viral. Twenty different countries: from radio, TV, and internet. Everywhere!
3) Any potential problems with study?
No, overall study looks good and that is what the publisher thought too.
However, let's dig a bit deeper!
4) Length of Study and is this a problem?
Study lasted 21 days, which is a pretty short period of time. A person's weight can fluctuate over said short period of time (eg. women can lose/gain multiple lbs during course of menstrual cycle).
5) Number of participants and is this a problem?
The researchers conveniently left this information out of the publication as the total sample was only 15!
A couple random changes (loss of weight) in chocolate condition could have been reason for improvement in weight.
6) Further Problems: Researchers included 12 other non-reported outcome variables (DVs) in initial study! In addition, researchers had no original (a priori) hypothesis about variables and chocolate. What problems does this pose?
Basically, chocolate influenced weight, cholesterol, and mental state. But, chocolate influenced NOTHING else (other 12 variables) which it likely should have influenced if chocolate is THAT good for you.
In addition, not creating hypotheses is bad. It's like throwing darts blindfolding and hoping you hit the bullseye. Certainly helps when the thrower has 15 darts (variables)!!! Bound to get something correct. In science this process of not making a hypothesis before the data is viewed is called: "HARKing."
7) Would this research surprise you if you found out it was all a hoax by the researchers!?!?
It was a hoax, they did all these problematic tactics and then some, just to show how easy it is to publish bad data in "some" science journals.
8) What takeaways do you have from this research?
Be skeptical of news claims, be skeptical of research.
Think if there were enough participants and duration to find appropriate influence.
Researchers can intentionally lie to get published or make unintentional mistakes.
Read actual published article:
Read more about the hoax story:
https://gizmodo.com/i-fooled-millions-into-thinking-chocolate-helps-weight-1707251800
Read the publisher's statement about article:
http://imed.pub/ojs/index.php/iam/article/view/1087/728
Read about how the publisher's likely lie:
https://gizmodo.com/chocolate-diet-paper-wont-be-retracted-becuase-it-was-1707531513
Read more about HARKing:
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