- your kidneys could probably process at least 8-10 litres of water a day, so youre not really drinking a dangerous amount of water, i just wanted to point out that there is such a thing... just something to keep in mind.
- for protein, just try to get 2-3 servings. the thing is, eating the correct serving amounts of natural or predominately unprocessed foods also ensures you get a wide array of other nutrients, so to have 2 servings of protein bars is not quite as balanced as having a protein bar, some natural protein (chicken and turkey are preferable to red meat, also fairly low on calories), and maybe some whey powder, which is kinda gross but a very "clean" source of protein. serving size is approx 100-200 calories, which will depend on what youre eating. 1 bar might be at the top end of that, something low-cal like chicken near the bottom (~3 oz or so?)
- it's really important for women to get plenty of calcium... so any sort of dairy that is a good source of calcium will work, if you can get used to it, fat-free options are good. in whatever's case, she doesnt consume dairy so she takes a supplement (smart girl!)
- on how many calories to eat a day: we all have what is called a BMR, or "base metabolic rate". this is how many calories we use in a day just... existing. as a general rule of thumb, you dont want to go below this or it will actually be counterproductive to your weight loss goal, your metabolism will drop (body goes into "starvation mode") and begins to break down lean mass along with fat for nutrients. if you are generally sedetary, dont excercise and have an office job, how many calories you actually burn will be about BMRx1.2. you can find your BMR
here... eating this BMRx1.2 amount will mean maintaining weight, aside from small metabolism adjustments your body makes depending on how much youre eating.
so im going to do myself: i am 6'3/200lbs/21yoa, so my BMR is about 2120 kcal. if i go through a normal day of work/walking around/etc i will burn 1.2x this, so 2550. if i want to lose weight, i should eat fewer calories than i use in a day, but not below my BMR, meaning i could consume 2120 a day but burn 2550, for a deficit of 430/day or 3010/week (1 lb of fat is about 3500 kcal, so id burn almost 1 lb a week). if i run for an hour i have burned another 1,000 kcal (numbers for different activities can be found online), which is added to my 1.2x value of 2550, meaning i have consumed 2120 but used 3,550 for a deficit of 1,430/day or over 10,000/wk (almost 3 lbs a week). this is why exercise is the only real way to lose weight faster, as compared to people who try and starve themselves and end up losing lots of lean body mass and looking all sickly.
exercising also gives an added benefit in the sense that, over time, you will lose weight and your BMR will actually go down, meaning it will be harder to lose weight as you get closer to your target weight. but if youre also exercising over time, you will develop muscle which helps burn calories and will curb this plateau. lastly, it is also easier to ensure you're at a calorie deficit when you have a larger range to "hit" with how many calories you've eaten in a day. trying to get between 2120 and 2550 is more difficult than trying to get between 2120 and 3550.
and yeah, you're getting the right idea with that breakfast item. you can't really go wrong with a balance and variety of whole or only lightly processed foods. then all you have to do is make sure you eat enough calories in a day (more smaller meals is better than fewer big meals) so your metabolism stays high, and then just use all those high quality calories you're eating to get some form of exercise.
oh, let me know if any of this doesnt make sense, i know it seems complicated but you can get the hang of it, then it becomes second nature!