The '98% success rate' weight loss claim that ignored the dropout problem

Saw a doctor on a morning show pushing this 8 week program and they kept saying 98% of people lost weight. Sounded amazing so I looked up the actual study. Turns out they only counted people who finished the program. Over 60% of participants quit in the first 3 weeks. Those people weren't in the 98% at all. Why do experts keep quoting numbers like that without mentioning who got left out? Has anyone else caught a stat like this where the fine print changes everything?

2 comments

2 Comments

kimw571d ago

Used to hear those numbers and just nod along, figured the science was solid. Then I saw a similar study on a sleep app that claimed 90% of users felt more rested, but they only tracked people who made it past day 14. Same exact trick with the dropouts and it really opened my eyes. Now I check the fine print before I get excited about any big success rate, especially anything to do with weight or health. It is crazy how a simple footnote about who they left out can flip the whole story. Have you found a way to spot these numbers fast before you waste an hour reading the study?

jake_patel12h ago

God, that sleep app thing is such a perfect example. The dropout trick is everywhere once you start looking for it. My quick rule is to just check the methods section for the words "completed the trial" or "adhered to protocol." If they don't plainly say how many people started versus finished, I automatically assume the number is inflated. Also, watch for percentages without the actual sample size, like "75% improvement" with no mention of whether that's 75 out of 100 or 75 out of 10,000. That little detail usually tells you everything you need to know before you even read the conclusion. It's honestly saved me so much time, I just skim for those two things now and move on.