The only thing that matters when it comes to weight loss is calories in vs calories out. Eat more calories than you need and you will gain weight, eat less than you need and you will lose weight. That really is it. Unfortunately it doesn't always APPEAR to be as easy, but honestly it is. Obviously nutrition is a different matter.
You could lose weight doing low carb as long as you're in a calorie deficit. You can lose weight doing intermittent fasting ad long as you're in a calorie deficit. You can lose weight eating nothing but big macs as long as you're in a calorie deficit.
There is so much bs when it comes to weight loss, much of which comes from so-called 'experts' trying to sell diet plans or some other crap you don't need. If what they did actually worked people would lose weight, keep it off and their source of income would disappear.
I've been losing weight for years. When I first started I was overly restrictive and limited myself to 1200 kcal a day. I'm 5"2 and all the tdee calculators told me I could only lose weight on that amount because I'm small. I was practically starving myself and this would lead me to binge frequently. If I managed to stick to the 1200kcal I'd lose 5-6lbs a week which is far too much.
Age does slow your metabolism but it'd really not as significant as you would think. There are no medications that cause you to gain weight (fat). Some medications can increase your appetite, others can cause you to retain water, others can make you feel lethargic causing you to move less and therefore burn less calories.
Low carb isn't a magic weight loss remedy, water is involved in the metabolism and storage of carbs so if you stop eating them you'll see the scales go down a huge amount really fast, but it's just water, not fat unfortunately and you'll gain it all back as soon as you start eating carbs again.
Many healthy foods can be quite high calorie, such as nuts, brown bread, pasta, rice etc. Salads can be astronomical in terms of calories if you're adding dressings, croutons etc so some people are genuinely surprised to find out how many calories they're consuming as they're eating healthy foods
It takes time to lose weight and many people are too impatient and give up before they see results. Weight and food is a very emotional topic for people so they look for a quick fix and get frustrated when things don't happen quickly enough for them. You really need at least 4-6 weeks to see any real progress, especially if you're a woman. Fat loss is slow and women tend to retain water around ovulation and their period. So if you've stuck to your calorie goal, you weigh yourself week 1 and you've lost 1lb, great! In week 2 you're ovulating and you're up 3lb you start thinking it's not working and you've actually gained weight but it's just water. Same just before your period, so you it's easy to see why someone might think that. However next time you weigh yourself the excess water weight is gone, you're actually down 2lb (of Fat) overall buy its taken 4 weeks to be able to actually see that on the scale because of all the fluctuations throughout the month.
I'm at a healthy weight now but I still feel a bit flabby. I have some wiggle room and am continuing to lose weight slowly. Last week I ate over 2000 calories most days, over 3000 calories one day and I lost 2lb.ive figured out from my own data that I need as 2700-2900 kcal a day to maintain my weight, far more than any tdee calculator tells me. I stick to this and the numbers always work out. If I eat a high carb or high salt or sodium meal I'll retain water for a few days and I know that(for some people it can be a week) and don't panic. I don't genuinely retain water at any point during my cycle, I'm not sure if I'm lucky or if it's because I'm on the pill so I don't have such huge hormonal fluctuations.
I'm sorry for the book ivet just written but this is a subject I've looked into A LOT, and it really surprises me that people don't realise how simple it can be, and that you really don't have to be miserable while you're doing it.