Something I have ALWAYS wondered but have never been able to find a real answer for: why is it that we gain weight back so easily? For example, when watching The Biggest Loser (I'm not actually a fan, but my mother is) one poor guy was in the hospital due to injury, and just from eating hospital food and not exercising for three days, he gained five pounds! Whereas a "normal weight"ed person wouldn't see that kind of increase in such a short period of time. Why is this? And does it ever end?? Because it's incredibly discouraging to see weeks of hard work vanish with one bad decision or one illness, and it's starting to make me think this is all pointless.

I don't know. For the example you gave, that's water gain not fat, in only 3 days. Plus, people in the hospital usually get IV fluids, which adds water weight pronto. I think that *would* happen to anyone.

I agree with Julie. Water weight.

Well, I would definitely hesitate to use the BL as an example of how to live your life (and lose weight). They use very extreme measures on that show to lose high amounts of weight on an ongoing basis (4-6 hours of heavy exercise a day combined with extreme calorie restriction for that level of activity), and it's also becoming more evident that they use very extreme measures to cut weight for weigh-ins (deliberate dehydration, extreme diet tricks, etc). Also, a "week" on the show isn't actually 7 days - as the hush-orders for former contestants are starting to break down, a lot of the details are coming out (see here and here and here and more)

So, briefly, if you were eating 1200 calories a day and working out HARD for 4+ hours each day, you're going to lose weight, but your body's going to be panicking! And when they do relax (or are forced to rehydrate), they gain weight. And, in all honesty, if you've ever been hospitalized on IV fluids, you know that it DOES cause you to bloat and retain a lot of fluids for a few days - which is going to make a major difference if you're already dehydrated as an attempt to maximize weight loss.


To answer the actual question - I think we do have a tendency to bounce weight back on for a couple reasons. A) Losing muscle mass (and just general size) and B) not changing the lifestyle - if someone is 300 pounds and eats 3000 calories a day, they might stay steady. If that same person goes "on a diet" and starts eating 1200 calories a day, their body is going to be struggling with the change and is going to both hold onto as much as it can, calorically, and breakdown both fat and muscle to survive. Which means, if you go back to eating 3000 calories, you're going to put on weight (at least in the short term) until your body starts to accept that food is no longer in "shortage".

That makes a lot of sense. Thanks for your answers, guys.

I guess I'm just hoping that someday my body won't be all "OMG, spare calories, I better hold onto these!" because it's really demoralizing to see things go down the toilet so fast.

Let's say a normal-range metabolic rate for someone sedentary who has not been dieting is about 2000 calories.

With a normal baseline of 2000 calories, it's still easier for most people to eat X calories more than that than x calories less. In other words, it's not too hard to eat 3000 calories per day but it is hard to restrict to 1000 calories/day (not to mention unhealthy).

For someone who has been dieting, the baseline is often lower. Bodies which have been dieting reduce their metabolic rate through a variety of mechanisms (including muscle wasting, increased cortisol levels, etc).

A lower baseline means it is even easier to eat X calories more than the baseline (and harder to eat X calories below it). Plus, folks whose bodies have been in starvation mode are often more vulnerable to cravings and such.

One of the best ways to fight this tendency in both the short and long run is to build muscle, which raises your metabolic rate (even at rest).

Doesn't it have to do with fat cells? Like, you can't reduce the amount of fat cells you have but you can shrink the fat inside them. So when you gain weight, you gain fat cells which means now there are more fat cells and they easily fill up so you gain weight faster next time?

I don't know if that's true or not - seems like something I've heard before. Maybe someone more knowledgeable can confirm/deny.

~choirgirl~

There are alot of reasons for weight fluctuations, some of them are easy to understand (but not control) and others are more mysterious.

One source is the infamous water weight gain. I retain less water and am least hungry on a low carb diet, so that's what I aim for. However, that also means that if I eat a higher carb one day, I can often "gain" several pounds of water overnight. I did that Sunday at my MIL's house where we were celebrating the birthdays of my husband, my SIL and myself. Now a serving of potatoes and a piece of birthday cake did not make me gain 5 lbs of fat, but I did gain 5 lbs of water (although carbs weren't only to blame, the protein at the meal was ham so salt contributed also). I'm already down a pound, and the rest should come off tomorrow (so the weight piles on quickly, but also falls off quickly if I don't continue more of the behaviors that cause the weight gain - whether it's fat or water).

Sometimes the weight of the food can cause temporary weight gain. High fiber and high water foods in the digestive tract can cause a temporary gain until digestion is completed.

There are other issues, and they are not pointless - it's just the work does have to be consistent and one week is not enough time to judge progress or lack of it.

Imagine if someone went to work and quit after one day on the job because they didn't get paid at the end of the day, or even at the end of a week, not understanding that payday only comes once or twice a month....

Or if you chugged a quart of water and stepped on a scale and then got ticked because you'd "gained" two pounds.

The payoff isn't always on a daily or weekly, or even for some unlucky folks monthly schedule. It's only consistency over the long haul that results are seen. Getting discouraged by the normal daily and weekly fluctuations, is more a factor of unrealistic expectations than a lack of progress or success.

I agree with not using them as an example, while I like the show.... it is not a true reflection of "real people" losing weight-- the way a majority of us do.

Whatever the reason we put weight on so fast I can say that in my opinion it is superhuman what all of us do that loose weight much less keep it off. If you have the problem of weight and are able to do anything about it it is dealing with a true monster that is totally on your doorstep all the time. We are all heroes.