Below tips use kilojoules because it's easier for me (kilojoules is the standard energy measurement used on Australian food packaging, plus 2,500kJ feels like a lot more than 600kCal ).
Here are my tips (focused particularly on 5:2 for men and the non domesticated):
1) You don't need to know how to cook, in fact it can be easier to fast if you don't know how. For the last few months I've been having a good quality ready meal (prepared fresh and chilled, not frozen) for lunch and nothing else food wise (usually Chicken Tikka Masala and rice liberally sprinkled with the hottest ground chilli powder I can find, I love Indian & heat). Just under 2,000kJ printed right there on the side of the pack, no need to think about ingredients, no careful measurements, there's your fast day arranged real easy (I know its 500kj under the 2,500kJ target for men, I just don't find I feel hungry enough need to eat more on a fast day).
2) You don't need to worry about eating interesting on a fast day: The point of the fast day is to fast, not to explore new realms of culinary delights. If you want to eat things you really really enjoy and have some variety, save that for the feed day. It's ok not to go searching for new sub-500kCal meals, feel free to find a small repertoire of meals you like that fit within budget and just keep repeating, keep repeating, keep repeating.
3) Don't worry about counting all calories, not even on a fast day: Sounds odd, but fasting is made so much easier by NOT meticulously counting calories. I usually eat 1 meal of around 2,000kJ around lunch leaving me with 500kJ for the rest of the day. I can drink as much no or very low calorie beverages as I want and don't bother about counting the calories. By low or no calorie I mean green or black tea sweetened with stevia tablets (calorie free organic sweetner which tastes great), sugar free soda (cola/red creaming soda/lemonade) and water. I would need to have 50 cups of tea or 35-50 litres of soda to use up the remaining budget. Clearly that's not going to happen. So, I don't have to stress about counting calories at all, I know I'll be below budget.
4) Do High Intensity Interval Training as late as possible on fast days (I usually start around 9:30pm as gym in my building closes at 10pm): Because I fast 3 days a week, I get the 3 days a week of HIIT sessions which is supposed to be enough for improving cardio health, insulin improvement etc. I don't have robust science to back this up, but my reasoning for doing HIIT late on a fast day:
- studies say training for men on a fast day is beneficial;
- according to exercise physiology books my dad checked out of his Uni's library, ratio of 1:3-5 is particularly effective for glycogen depletion (I usually do 20 second sprint, 80 second moderate pace for 1:4 ratio);
- HIIT is supposed to increase metabolism for hours after, makes sense that the elevated metabolism occurs at a time when your energy from food is most depleted and your body is burning fat.
5) Try a more severe fasting regime just to see what it's like: for 5:2ers out there, try the next one up. When I started I only intended to do 5:2, but after the first 2 fast days (Tuesday, Thursday) I felt like it was easy and I cracked on for a 3rd fast day on the Sunday and, lo and behold, I was a 4:3er. A few weeks ago, ADF fit nicely with my calendar so I've been doing that for 4 weeks and I'm pleased to find it's also easy, though noticeably tougher than 4:3, but still physically doable. Although ADF has been possible, I will be very relieved to return to the much easier 4:3 from next week onwards, so I think it's been a worthwhile experience vis-a-vis . Also, doing the more severe form of fasting has convinced me that IF is a permanent solution to weight control in that, if you can easily cope with 4:3 or ADF, 5:2 and then 6:1 will be a breeze.
6) Always have something to look forward to at the start of a feed day. I love sausage rolls. I used to have one a week. Now I drop into my nearby bakery 3 days a week. Many a fast day has been made much easier by the knowledge that a sausage roll was not far away.
7) It can be ok to eat out on a fast day so long as you plan ahead. Last week some friends wanted to grab lunch on one of my fast days. So I steered them towards an eatery where I knew I could get a meal I liked for around 2,300kJ.
Anyway, that's enough for now.