This page is to serve as an explanation and note about point values. All posts before 11/30 are the old point system. All posts after that date will be noted as to which system (if not both), was used.
The Points Plus is supposedly based on a better understanding of how the body processes food. It is based on fat, fiber, protein and carbohydrates. In general, most items go up except or protiens, which remain about the same and fruit, which becomes free. While things go up, so does the daily allowance.
The point calculation is more complicated but, after a good bit of playing, I deduced a working model for it. Note that it may not be perfect, but it does seem to work in every situation I have encountered and tested (including very high values and values near rounding points.
The formula is as follows. Note that, at least as of this writing and based on WeightWatchers.com, there does not seem to be a cap on fiber, but it does not take much away.
Points=round((Fat)(9/35) + (Carbs)(19/175) + (Protein)(16/175) – (Fiber)(2/25))
Please make sure to leave a comment if anyone finds where this does not work.
A less accurate version that can be easily done in your head is as follows:
Points=round( (Fat*3 + Protein + Carbs – Fiber)/10)
It is not overly accurate but it is easily doable in your head.
Another in-your-head method that is a bit strange and hard to test looks at how carbs, protein, fat and (I think), fiber contribute to calories. It is great because it can be done when only caloric information is available.
It should be fat/28 but it is easier to be fat/30
There is no clear way to deal with alcohol because they do not tell us. However, as noted in the Wikipedia talk page, if 1.5 oz whiskey (which is 40% ABV) is 4 points. According to Wolfram Alpha, 0.6 fl oz (40% of 1.5fl oz) is 14 grams of ethanol (alcohol). If 14 grams of alcohol is 4 points, take grams/3.5 into the points calculation.
Old Points System
The old system, phased out on November 28, 2010, was based on calories, fat and fiber. It can be roughly thought of as 50 calories/point with a bias towards fiber and away from fat.
The exact point calculation is:
round( (calories/50) + (grams fat/12) – (min(4 or grams fiber)/5) ).
This is mathematically identical to counting each gram of fat as 50/12 calories and fiber as 10. Then add the “fat calories” to the calories and subtract the “fiber calories” but no more than 40 “fiber calories”. Divide that by 50 and round.
While not exact, it is easier to count fat as 5 calories instead of the actual 50/12=4.166. This is an over estimate but it is easier to do in your head.
In addition, vegetables are basically zero even if they have some calories, but I do start to count things if there is a lot