When I search a food on MFP I always scan through the results and try to select an option that A. has all the nutritional information updated (iron content etc) and B. is in the higher calorie end of the range. I would rather over count than under count.

Yes. And they can not only be off by 20%, but that's per serving size. So if you are eating from a container that has several servings, the final calories can be WAYYYY off. And, they can round down to the nearest 5 calories. All of those things add up. 100 calories per day is ten pounds in a year.

On top of this, as an RNYer I am still malabsorbing some fat, forever. Studies disagree on how much, and in the real world, it really doesn't matter for weight maintenance. But it further throws off my daily calories. A day with lower fat and higher carb, for me, very well may have more calories than a seemingly equivalent calorie day of higher fat and lower carb.

When I say how many calories I am eating, I am aware it might be way off. But it's the best yardstick I have, and far, far better than eyeballing food. I personally look at my "calories" more like points. Because I eat a pretty small range of foods, I may be off on the actual calories, but I am going to be off consistently over a longer time period. My points, calories, or however I label them may not be scientifically valid, but they do keep my weight in a steady range.

Fitbits and other trackers lie/are off too! So think about...20% off on food 20% off on "calorie burning" and next thing ya know, one has consumed and/or not burned off about "40%" of what they thought.

That is why we should NOT eat our calories back after exercising. Exercise probably eats away at that incorrect 20% cushion

Amen.

The machines at the gym tell us they burn about 3 times as much as they actually do.

As it has been explained to me by my surgeon and in multiple articles, having weight loss surgery, at least the RNY, doesn't just restrict the intake, but also resets your metabolism. That is why WLS works and losing weight with diet and exercise alone is so freaking hard.

I could never have lost all the weight that I have without surgery.

Short answer No. Get the weight off. Follow the rules. Maintenance is a different ball game, and I think that is where everyone has to figure out for themselves what works. Much less 'one size fits all' than weight loss. I considered myself a human experiment....

I did find RMR testing helpful in maintenance as it showed me I could work myself up to more calories. But I took what they considered the minimum and made it my maximum. Calories are in a larger range too... some days more, some less depending what I'm doing and eating.

No. Metabolism just doesn't work like that.

https://www.verywell.com/what-is-metabolism-and-how-do-i-change-it-3495537

I certainly don't think my metabolism is higher than pre-op. I definitely eat less these days than I did pre-op, as well as eating much more nutritious foods than pre-op.

I also move my ass a lot more than when I was 100 pounds heavier.

I've never seen any legit research on pre- and post-op metabolic changes. Most of what I've heard is lots of rah-rahing.

Self-reported eating behaviors are notoriously unreliable. In fact, the only eating self-reports I trust are my own. ;)