Don't forget the coffee! You can get everything you mentioned just from caffeine!
Don't forget the coffee! You can get everything you mentioned just from caffeine!
"As you can see, the Fullness Factor does a reasonably good job of predicting the satiety responses, with the possible exception of potatoes. Note, however, that the methodology of this particular study may have contributed to an artificially high satiety value for potatoes. Per the study's design, the participants were separately fed 220-Calorie servings of each food. A 220-Calorie serving of plain potatoes is larger and much less palatable than the other foods studied. The size of this serving may have influenced a repulsion to this test food that goes beyond the normal satiating response."
All sources I could find talk specifically of boiled potatoes, as opposed to e.g. mashed potatoes, and apparently they all go back to one study which was not replicated. You can trust it if you like, but don't pretend that everyone else should. Read Ionnadis ("most published research is false"), and the recent nature cancer reproduction report (48 of 53 highly celebrated results about cancer that were published in Science and Nature were not reproducible).
They have an extremely good match for everything other than potatoes. The right thing to do, practically, is to ignore the outlier for most statistics on one hand, and to try to reproduce the outlier results on others. Theoretically, you would believe nothing and do everything again (and again) until you have perfect correlation between theory and practice.
Either way, every google search I've found says "potatoes are the exception" and they all seem to trace back to one study. Trust it if you like, I don't.
This website describes a simple regression (with 4 to 9 degrees of freedom depending on your underlying assumptions, let us assume 9 which is the "worst") that has a good match to that data of 38 points; if you are familiar with the quality of nutrition "science", this is actually extremely good match - e.g. atwater factors are often 30%-50% different than expected (and assumed "ground truth" based on 100 year old measurements) when actually measured. You have to not trust either atwater or the more recent measurements - possibly both.
Now, this regression, seems to hold very well with the exception of potatoes. From this, personally, I would infer either (a) a mistake somewhere in the data collection or (b) potatoes are special among the foods tested in a way not captured in this regression.
Actually working in data science for a living for a few years, my experience is that the practical thing to do is to drop the outliers from your dataset on one hand (so that your regressions and descriptions are robust with respect to the data that you DO consider) and investigate the outliers on the other hand, to figure out if it's an error in the input or a missing input (e.g., I would guess measurements like "water per cm^3" and "weight per cm^3" might be good measurements - if I had a proper "test set" to validate them against; just adding more measurements is usually NOT what you want to do).
Potato could be special in its effects on hunger / satiety - I don't know. e.g. among common food items, fresh eggs and fresh milk are special in the sense that, unlike any other "single" food item, they are each individually enough to sustain life. But based on the data I can find by googling (hardly anything to base policy on, but what I personally used as input) - I assume that, for whatever reason, potatoes are an exception to the general rule.
You may disagree, but I hope you at least understand my response.
The website's numbers are not a dataset. Again, it is made up numbers by a random website. There is no evidence behind it at all. The study's numbers do not have outliers, you only want there to be an outlier by comparing the dataset to completely made up numbers with no basis in fact.
Did we look at the same website? They give the formula by which they derived the numbers, based on "standard" nutritional data for those foods. It's not a dataset per-se, it is (supposedly) a simple and easily reproducible computation of a widely available dataset. (No, I did not try to reproduce though I would if I were going to take any action based on this).
Why would you assume it is random?
And I ask, again, if you can point me to the two independent studies that confirm potato's properties, because I can only find one.
Because it is? If I just say "here's how filling food is: calories * pi * r2", that doesn't give you a data set, it gives you made up numbers.
And if you believe (as I do) that all of this is entirely unscientific, but some of it is sort of useful - than what exactly are you arguing?