This times ten. The stomach isn't some fuel tank that if you put too much in it stores the extra fuel. I lost weight at 4K calories a day and I've gained it at 1.5K/day. All while maintaining the same amount of exercise. Really from just cutting out sugar, grains and starch, I moved my cholesterol from slighty bad to really good and cut triglycerides from 150 to 65. Plus lost 43 pounds. In 4 months. While cramming my face at nearly every meal.
Yeah I don't know bud. The human body is pretty good at not wasting calories, and there's no way to double or triple your base metabolism like you're describing. My guess is you're measuring water weight, and confusing dehydration with weight loss. Maybe you ate a whole bunch of salty food and your body had to use a bunch of water to flush it out. The fact that you lost 43 pounds is telling, it means you were at least that much overweight to begin with, so the fluctuation day to day is going to be quite large. Once you get into shape enough to consider yourself an athlete, no way you can eat like that and not gain weight, unless you have the muscle mass of Michael Phelps, and spend as much time as him training too. Hiking up and down Mount Washington, for example, is going to burn maybe 5000 calories, assuming you don't eat anything on the way up or down and drink only water. But you can't hike Mt Washington every day and keep your knees and your job. So you can't possibly need that many calories.
And yet the research keeps pointing in a single direction. Low carb diets improve cholesterol and triglycerides, and reduce weight. No one thinks that when you eat 4K calories of bacon, butter covered vegetables, and more bacon, that your body is actually making use of all that energy. But if you eat cereals, sugar, and potatoes, there's quite a bit of evidence that your body does make use of it all.
I'm sure your advice is well intentioned, but I'll go with what the research keeps alluding to.
Your source makes no mention of calories (in fact, the term is not used on the page whatsoever).
Low carb diets are effective, and it's in large part because people on low carb diets eat fewer calories.
Your body (not your stomach) IS a fuel tank that stores the fuel it can't use. That's a very apt description, actually, except that you said it was not.
You know though, in all fairness I'm being really way too negative. I'm sorry about that- not my place. You know I came across this really cool website called nerd fitness which has mottos like "join the rebellion " and "level up your life" and it sounds dumb but it actually really helps me to get motivated.. It's funny too and they walk you through how to do a push-up, a deadlift and so on. And they have lots of info on nutrition too, they tend to be paleo fans.
If you eat 4 kcals worth of bacon a day, my friend, you are not going to die of old age. I hope for your sake that I'm wrong. But yeah, I would suggest that your body is storing or using the majority of that energy.