1. People who eat ZERO whole plants.
They get zero "plus" points on the first four questions, which means that their entire diet is comprised of animal based and/or processed foods. They will more than likely score somewhere between -21 and -44, which is the range for the "Unhealthful Diet" (UD) level of eating, more than likely deriving less than 10% of their calories from whole plants.
2. People who eat nothing but whole plants.
As such, they get zero "minus" points in questions 5 through 12 so their entire score depends on just the whole plant foods in questions 1 through 4 (categories where they consume ALL of their calories). Hence, they will almost certainly score at +30 points or better--which is the beginning of the 4Leaf range of our 88-point scale.
Now that we've covered the extremes, all we need to do next is divide the remaining possible scores, from -20 to +29, a total of 49 points, into the other four groups:
Better than Most,
1Leaf, 2Leaf and 3Leaf.
That's what we've done with our 4Leaf scale and I now believe that we can rest our case that the numerical score ranging from -44 to +44 is a fairly reliable indicator (data-based
) of the percentage of one's daily calories that is comprised of whole plants.
It's not precise, but it doesn't need to be. It's kind of like sailing. You don't need to know the exact speed and direction of the wind in order to be a great sailor. You just need to know how to set your sails for the general direction you want to go--then make adjustments as you go along.
This conclusion is reinforced by the fact that, over the past six years, we've received a great number of unsolicited kudos about the survey compared to less than TEN complaints--after hundreds of thousands of iterations. That tells me that this survey has passed the test of time and should be used with confidence.
The Bottom Line. Our 4Leaf Survey does a great job of identifying the 90% of the Western population who need a lot of help in understanding what comprises an optimal diet for humans--one that is effective in truly promoting health.
These are the billions of people who will score at the UD (Unhealthful Diet) or the BTM (Better than Most) level on the 4Leaf Survey. If they are honest about what they're really eating, their scores will not climb above zero on the 4Leaf scale.
And the 4Leaf advice to all of those billions of people is consistently the same:
"Work on replacing most (if not all) of your animal-based and highly processed meals & snacks with whole, plant-based foods."
What about risk? I have concluded that there is absolutely zero risk in using the 4Leaf Survey--yet there is a great deal of upside potential. I am talking about the desperate need for a rapid, global dietary shift toward widespread consumption of whole plant-based foods--for our health, our environment and our future as a species.
The 4Leaf Survey was not designed to be precise and doesn't need to be precise to be effective. It just needs to enlighten the consumers of the S.A.D. to the fact that they are eating nowhere near the healthy diet that they think they are eating.
Dr. Kerry Graff (my co-author) has found the survey to be a very effective tool for actively engaging her patients in the process of making huge improvements in their diet. Often, after completing her/his first survey, the patient exclaims:
"Oh my God, I thought that I was already eating a pretty healthy diet!"
After just turning a few of their routine meals into super-healthy 4Leaf meals, those patients will receive some positive reinforcement in the form of a higher 4Leaf score the next time they take the survey.