Just came across a really poor weight loss study

thestate.com/2014/11/09/3802103/usc-study-finds-vegan-diet-most.html?sp=/99/117/

Looking for some studies for a few assignments, found this article. Thought I would post this one here, to emphasize that just because a study/newspaper says that x causes y, or x is better than y, etc. doesn't mean that the study was actually well conducted or that it isn't without it's very obvious limitations. Hypothesis is that vegan diet = better weight loss.

some glaring things that popped out at me from the actual paper:

1) Few participants in each group (~12 participants in 5 groups)

2) No information given to participants on caloric intake/restriction/monitoring. Simply told what foods they could and could not eat.

3) The control group (standard omnivore diet) was given an example menu that contained some higher calorie foods compared to the vegan group, and the groups in between had recommendations that fell in between these two outer groups. So of course, right off the bat they are given a lower calorie recommendation.

4) Participants filled out "dietary recalls." I have no idea what this means - did they basically just write down or say what they had eaten previously? Or did they write things down as they ate, as we do while logging our food?

5) They use a table listing information such as caloric intake. However, the authors do not point out anything about how this information was gathered (was it just those "recalls" or was it daily logging? i highly doubt the latter because they say that the point was to find a dietary method that doesn't need to be employed with logging etc).They also show that the vegan group had the highest caloric intake of all groups.

6) Vegans decreased their protein and fat intake the most from all 5 groups. So there is a good chance that participants were not eating as many calories as they believed (fewer calorie-dense items), while also losing more muscle mass than other participants.

7) All groups lowered their caloric intake over the 6 months, with vegans reducing calories the most from baseline (e.g. the numbers for vegans is given as -903 ± 1238; omnivores -194 ± 377). I'm not entirely sure what the +/- is indicating - if that means that this is the margin of error, that is huuuge.

8) Less than 50% of participants per group actually adhered to the diets for a full 6 months. Only 33%, or FOUR participants, from the vegan group stuck it out, compared to like 40ish% for the rest of the groups. So high attrition for every group; I'm really seeing problems with this study's external validity.

I cannot link the full article, but if anyone can find it for free then definitley link it if others are interested in reading it.

But I've seen some posters regularly say "this and this was proved in a study" and either don't link the studies or if they do then it's a link to a news article that likely doesn't even link back to the original source. So just because a study says so, doesn't mean it's proven fact. Also that even though the authors say the goal was to find a way to lose weight without tracking calories, the vegan group by default would be eating fewer calories compared to the others if I read the table correctly (really poorly laid out table, by the way). Calories in < calories out!