Flexi syn days are where you pick a number of syns you will go up to, eg 60, and stop eating syns once you have reached this number. You then go back to eating normally the next day, without putting your body under the strain of starvation. Some people mistake flexi syns for when you have more of your weekly allowance one day, and then cut back the rest of the week. If it isn't possible to work out the syns of your meal, it will be hard to flexi-syn.
Hope this helps
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