Why am I gaining? I’m so confused!

Trust the process. If you're sure you're at or under 1600 calories, the weight will come off. Don't worry so much about macro goals. They're way over-hyped on here. Also, be aware that "eating clean" and eating to lose weight are 2 different things. Perfectly healthy foods can have a lot of calories and cause weight gain. Also, if you're getting full before reaching 1600 calories, I'd let it be and not worry too much about it unless you start dropping way too much weight too fast. Listen to your body.

You might need to adjust your settings - 1600 may be too high. If you set for very active but aren’t very active outside of intentional exercise, you might be eating at maintenance or possibly a little over.

OP, I agree with others that water retention from new exercise may be a very meaningful factor in why the scale isn't dropping yet. The 50g protein minimum sounds reasonable to me (as a similar sized woman, 5'5"), but 173 calories of protein is unnecessarily high IMO, especially if much of your protein comes from meat/fish/dairy sources.

A possible factor is that some macro calculators will estimate protein based on current weight, rather than basing it on a healthy goal weight. We don't need massive amounts of extra protein to keep our fat mass healthy, it's about supporting our lean mass.

There's an evidence based protein calculator here, with its explanation:

https://examine.com/protein-intake-calculator/
https://examine.com/guides/protein-intake/

If you read the explanation closely, even they say that anyone substantially overweight might want to consider basing protein on goal weight. The site has a reasonable reputation for following the science, and they don't sell supplements so they're not motivated to pump up the recommendations.

On top of all of that, while it isn't the most common pattern, some women report only seeing a new low weight once per month, at a certain point in their menstrual cycle. (Yes, hormonal water retention can be that weird.) At 43, I'm guessing you may still have cycles. Stick with your new routine at least long enough to compare your weight at the same relative point in at least two different cycles. Then you can adjust intake based on your own experience.

A very common thing, as others have alluded to, is to expect weight loss to happen fast, and at a steady rate. That leads to diet-switching or giving up way before the real results are in. In a body that can be 60% plus water, multi-pound water weight fluctuations from one day to the next are going to outpace the gradual rate of fat loss (which actually may be happening more close to linearly behind the mask of water fluctuations).

Think about it: Even at the very fast loss rate of 2 pounds a week - a rate that's unhealthfully fast for someone at 160 pounds, generally - the fat loss would be about 4.6 ounces per day, on average. That's the weight equivalent of slightly more than half a cup of water.

This thread, and especially the article linked in the first post on the thread, would be a good, informative read:

https://community.myfitnesspal.com/en/discussion/10683010/the-weird-and-highly-annoying-world-of-scale-fluctuations/p1

You may lose weight on 1600 calories, or not. But it's too soon to know, after two weeks - under any circumstances, let alone with new exercise and a change in eating habits in the picture.

CharlieMonkeybear wrote: »

You may gain weight from muscle mass first of all because muscle weighs more than fat. Also, the more muscle you have the faster your metabolism will be. This also means your resting metabolic rate will be higher like when you are just watching tv or sleeping.
You will have a better sense of if you’re making progress by how your clothes fit. Also, you need to remember that this is an app. It’s a generalization.

Things like bmi and calorie amounts were originally standardized for adult non-hispanic caucasian males, then adult non-hispanic caucasian females. Research now shows that these measures are not accurate for Asian, Hispanic, Indigenous and Black populations.

Not everyone’s body is the same in terms of metabolism and we can really mess up our metabolism with dieting and it takes time to recover.
Also, weight loss and gaining muscle is just harder after age 40.

Don’t be so hard on yourself. And you need enough food for sure, but you shouldn’t be making yourself sick. If you can afford to go see a dietitian I would suggest that rather than trusting an app.
You are unique with a unique history.

I know you're trying to encouraging, which is great; but it's important to be realistic, since over-optimism can set people up for disappointment in the longer run.

And it's true that MFP (and other calorie calculators and fitness trackers) give us a goal that's the average for people similar to us. Consulting a registered dietitian can be very helpful, but a low tech way to adjust calorie goal is simply to treat the MFP (or other) estimate as a starting point, stick to it for 4-6 weeks (whole menstrual periods for those to whom that applies), then adjust calorie goal based on actual results. That can even compensate, to some extent, for less than ideally accurate calorie logging.

Under ideal conditions, gaining 1-2 pounds of new muscle mass per month would be quite a good result. Most anyone can gain muscle mass with the right combination of factors, which include a calorie surplus, a good progressive strength training faithfully performed, and good overall nutrition (especially but not exclusively adequate protein), among other things. Since one of the favorable factors for faster rates of muscle-mass gain is relative youth, OP at 43 can find ways to make gains through persistence and patience, but as you observed, realistically it's going to be slower than 1-2 pounds per month.

On the flip side of things, half a pound a week is about the slowest rate of fat loss most people would find satisfying, and even that can take multiple weeks to show up on a bodyweight scale amongst routine (irrelevant) multi-pound day to day body weight fluctuations caused by changes in water retention and digestive contents on the way to becoming waste.

A sad but inescapable conclusion is that it's extremely unlikely that OP has gained enough new muscle mass in two weeks to outpace meaningful fat loss.

That doesn't mean fat loss isn't happening, because others have a point that water retention is a thing that actually can mask fat loss, sometimes for a surprisingly long time, as noted above.

Researchers believe that a pound of muscle at rest burns around 6 calories or so per day, maybe 10ish according to optimists. A pound of fat, which is also metabolically active, burns around 2 calories per day at rest. That 4-8 calorie difference per pound per day is not a huge metabolic boon - also a sad thing.

It's true that muscular people often do tend to have higher TDEEs than unmuscular ones in practice . . . my strong suspicion is that a big part of the reason is not metabolism, but rather the probability that it's more fun and easy to move when strong/fit, so strong/fit people move more in all aspects of life (not just exercise) and burn more calories that way. Strength exercise is absolutely worth doing for a wide range of reasons, but the metabolic bonus is pretty low on the list in effectiveness terms.

I wish it were otherwise, but that's what I think is true: Multi-pound scale weight changes (absent a dramatic change in eating or exercise) over a few days to a month are likely to be about water retention and digestive contents; fat gains or losses may show up - stop playing peek-a-boo on the scale with water/waste - over weeks to a small number of months depending on loss rate; and meaningful muscle mass gains are more about many weeks to many months.