Please forgive me if I am misunderstanding your question and answering below in a way that isn’t what you mean.
I believe for this to work you have aim for:
• a reasonable number of calories (for me this is 1200-1400 a day)
• and about 30g of fat a day with no more than 15g of fat in a meal
• and some sweaty exercise most day.
On the food front you need to add up what you are eating each day. So for example today I have had 1282 cals and only 22 g of fat, which is too little fat for me to do well today and I should have planned it better. This is what I ate - the first figure is cals, the second is g of fat ( it looks better on my spreadsheet but I can't seem to lay it out properly here)
Oat So Simple Original 98 2.3
180ml skimmed milk 58 0.4
cod liver oil capsule 10 1.0
Cup of coffee splash of skimmed milk 10 0.1
9 almonds 55 5.0
salad 30 0.6
bowl of fruit salad 200 1.0
25g cooked chicken 38 0.9
Cup of coffee splash of skimmed milk 10 0.1
Cup of coffee splash of skimmed milk 10 0.1
156g wholemeal bread 339 3.9
prawns 154 0.2
low fat mayo 17 0.7
salad 30 0.6
6 walnuts 50 5.0
vanilla yoghurt 65 0.0
400g strawberries 108 0.4
Yesterday I had 1168 cals and 29g of fat which is a bit more like it. It consisted of:
Oat So Simple Original 98 2.3
180ml skimmed milk 58 0.4
cod liver oil capsule 10 1.0
9 almonds 55 5.0
3 coffees splash of skimmed milk 30 0.3
prawns 130 1.6
salad 30 0.6
apple 53 0.1
banana 110 0.6
6 almonds 37 3.3
2 brazil 43 2.0
5 hazelnuts 37 3.6
Cup of coffee splash of skimmed milk 10 0.1
co-op Healthy eating lasagne 370 8.4
diet coke 1 0.0
Del Monte raspberry smoothie lolly 96 0.0
You have to look at the weight of the portion – or weigh it – and then if it is say 225g you multiply the cals per 100g by 2.25 to get the cals in your portion, and the fat per 100g by 2.25 to get the fat in your portion. If you add this all up every day until you get the idea, you can stay in the right zone.
Sorry again is this is too detailed and obvious.