So..why isn't it as simple as calories in/calories out?

as a semi-scientist I do believe it is a matter of calories in and calories out,

I do not 'believe' in the starvation thingy,

having that said there are factors, like scrupulous record keeping, at one time I measured an apple as an apple until one day I weighed my costco apple and found it was more than twice the weight as the 'average' apple, more than twice the sugars, more than twice the calories, and I was eating several per day,

water retention, inflammation, while not fat, makes me just feel worse, when I watch my sodium, and I have a goal of under 1000mgs, I feel more like walking etc,

I have tweeked my goals lowering my calories to maintain a 2 pound loss after each pound I lose, it requires lowering my daily allowed calories,

but each calorie I eat now MUST have maximum nutrition, I MUST maximize fiber, protein, vitamins etc,

I also must hydrate, without pounds and pounds of food, the body needs at least water to keep the system pumping,

The end result of weight loss is ALWAYS Calories IN < Calories OUT.

However a couple things can get in the way of that.

1) Protein intake. Eating more protein can give you a slight metabolic advantage over eating less of it.

2) Inadequate caloric intake. This can lead to less energy expenditure whether obvious (fatigue) or not so obvious (lack of desire to be physically active). Calories IN and OUT are coupled, they are not independent. Changing one can affect the other.

3) Water retention. Several pounds of water can be retained in the body even as fat is being lost. This can mask fat loss for weeks at a time. I've heard water weight of up to 10 lbs in some people. I'm on a low carb diet so my glycogen stores are usually low. On a day of carb binging I have raised my weight by 8 lbs without any fat gain, just water.

4) Insulin resistance. If you are insulin resistant and eat lots of carbs, you will struggle with weight loss. If you reduce carbs and your insulin levels, the weight will start melting off. This happens because your hunger/eating decreases and/or physical activity increases because your body can now freely burn fat.

5) Accuracy of record keeping. And of course people tend to underestimate calories consumed and overestimate calories burned.

it IS simple - do more, eat less (same as calories in<calories out) :flowerforyou:

I agree with the OP that it is not that simple. The makeup of those calories is important. Regardless of any study for and against, our own bodies and experiences are the litmus test. Put simply, if I eat less pasta and grains and more proteins at the same calorie daily totals (for me about 2300 cal/day), I lose fat / drop weight more quickly.

I do believe it is as simple as calories in/calories out, BUT hormones will also play a temporary role.

Leptin, which is produced by fat cells, normally causes a certain amount of satiety--> feeling not hungry.
The more fat cells, the more leptin is circulating in your body all the time. Reducing those fat cells, reducing leptin, and all of a sudden you start to feel hungry!

Ghrelin is the opposite, it makes you feel hungry and promotes weight gain. If you don't get enough sleep, your levels of ghrelin will rise and you'll feel hungry.

And then of course there are the corticosteroids, which your body produces from STRESS and helps deposit extra fat around the abdomen.

Insulin, as mentioned above, is another biggie.

So temporarily, your body might be holding on to water and/or nutrients to try to balance itself out, but in the end the calories will prevail. :happy:

another thing that helped me was the book The End of Overeating by Kessler, a very big real scientist, lots of science here,

his conclusion: there is an insidious triad: SALT/SUGAR/FAT that we are somewhat predisposed to favor, but lately programmed to crave,

think back. you eat something salty and then for some reason want something sweet and the cycle continues, many food manufacturers actually load their foods with extra salt and sugar, corn syrup etc, so your taste buds are bombarded,

trust me, just a few days on a low sodium diet reveals just how salty processed food is,

to return, and of course salty or sweet---everything tastes better fried, or slathered in butter, setting up the cycle again,

the good news is that the addiction to these evil 3 can be broken, or at least tamed,

it takes work, but I am a lifelong fatso and really was worried I would never be able to not really CRAVE these things,

but it gets better, it does,

and in the process I am healing,

I have been a fat MALNOURISHED person,

I am healthier,

this is for the rest of your life,

you need to make whole life decisions,

buy and consume healthy food, you deserve health