I’m 5’ 4” and was always between 9st 5lbs and 9st 12lbs. In the last couple of years I have gone up nearly a stone and feel too heavy (menopause related) so can’t imagine how you feel.
Throughout my life my weight has been consistent. I know some people swear by fasting but I’m not honestly convinced myself. I eat three meals a day; breakfast, lunch and dinner. I do sometimes have the odd snack but it is the exception rather than the rule. It also makes quite a difference to my waistline when I don’t indulge.
I’m not a diet expert by any stretch of the imagination but it does sound like you are eating quite a lot of processed carbs.
In terms of breakfast, the porridge is quite good. I would try to cut down on the cereal so maybe just have a handful of cereal with full fat yoghurt and some fruit. Eggs are really good too so a couple of eggs scrambled with some spinach (frozen will do), cherry tomatoes and a small bit of seeded/wholegrain bread.
Lunch – You would be better off to have a slice of bread and make an open sandwich with full fat butter and mayonnaise (in moderation) and then pile salad stuff on top and then a protein like ham, chicken, tuna, salmon or cheese (which is good as a sprinkling with the ham).
Dinner – A palm sized portion of protein and a carb like rice or pasta then lots of veg with some of your tomato based sauce. I’d have a few tablespoons though not a cereal bowl!
The thinking behind low fat has changed as often low fat foods are often laden with sugar. You’re actually better to eat full fat in moderation as it is far more satisfying and will sustain you for longer. I eat full fat butter, yoghurt, cheese, mayonnaise, etc.
Also, consider eating protein for breakfast, lunch and dinner because again that will help to sustain you and keep your blood sugar even. Try to reduce the amount of simple carbs you eat (bread, pasta, etc.). You don’t have to give them up completely but just eat more veg and green stuff. Of course, drinking water is excellent too.
Where did you get the figure of 1800 calories? I’ve never calorie counted but that does sound like a lot. British Heart Foundation recommend 1500 for a woman but I guess that is average intake so if you want to eat lose you need to eat slightly less.
The British Heart Foundation have some great leaflets you can download. One of them explains portion size which would probably be a good one for you to look at. As a nation, we’ve got into real bad habits and we actually don’t need to eat as much as we think we do!
www.bhf.org.uk/informationsupport/publications?keyword=&tab=publications&subject=healthy-eating&lang=english&run=1
What work do you do? Is it quite sedentary?