The FastDay Forum

OK i have a two part question.

question 1: it says "up too" 566 calories on my fast days, if i go lower how will that effect me?

question 2: on my feeding days it says "around" 2200 but before starting my 5:2 diet i was counting calories at my daily intake was ranging between 1200 and 1600, so my question is since my metabolism is already slow on daily basis from a sedentary life style as well as trying different diets including the daily counting of calories, should i stick with the lower calorie amounts on my feed days or would it be wiser to up my calorie intake on my feed days if my goal is to loss weight and i have no problem with sticking with my fast days.


I ask this since i know if you do not eat enough your body will go in starvation mode, i'm not afraid of this diet putting me in that mode, i'm just concerned that my body might ALREADY be in that mode and how my feed days will react with that.

I'll let people more knowledgeable than me answer you properly, but you might like to search this forum for posts on "Starvation Mode" there seems to be a lot of research that shows it to be a myth (I have no opinion either way)
Good luck

I don't think starvation mode is at all a risk for you following this way of eating whether you consume 1200 or 2200 calories on feed days. Starvation mode occurs with real starvation.

You will lose weight faster if you stick with lower calories on the feed days, but you may find it harder to sustain over the medium/long term, and if the way of eating isn't sustainable then it is a failure (this one is for life, right - even those of us who have reached our target still have to fast!) Most important thing is to eat 'sensibly' on those 5 days and not to 'let rip'. Occasional treats of course are allowed!

Some people here have found that under-eating on their feast days paradoxically decreased their weight loss. From your stats, it looks like the diet is working for you as is, so perhaps it's not worth questioning it. Having said that, maybe for sustainability you might want to gradually increase your feast day calories.

I'm a "starvation mode" sceptic. Obese people have enough fat reserves to supply their entire calorie need for weeks and weeks, so a food intake that provides enough protein to head off muscle loss along with essential fats, minerals and vitamins will be adequate without needing to stress about hitting a calorie goal. With the usual rider about discussing it with a doctor etc.

So my answer to 1) is that you can have zero calorie or water / zero calorie drink only fast days. Michael Mosley's 500-ish calories is a compromise to allow people to stick to it, nothing more. It's up to you.

On 2) you were previously eating 1200-1600 as a continuous calorie reduction, let's say 1400 a day or 9800 a week. If you wanted the same deficit on 5:2 with no deficit on feed days you should aim for :

500 * 2 = 1000 on 2 fast days

9800 - 1000 = 8800 / 5 = 1760 per day on feed days

Or if you did zero calorie fasts 9800 / 5 = 1960 per day on feed days.

the most recent thing i read about starvation mode seems to point toward myth as well, wish i had read that before posting this actually feel kinda silly now XD but i really appreciate all your reply's and i find them helpfull ty!

[carorees]

Starvation mode as described by many (your body will hang on to fat and you won't lose weight) is patently a myth...otherwise no-one would die of starvation! However, a decrease in energy burned as you lose weight is not a myth. As there becomes less of you it takes less energy to run your body and to move it around. There is also a tendency with prolonged calorie restriction to move around less, to eat more than you think and for your body to conserve energy by decreasing metabolic rate. All these things combined can add up to a situation where your daily calorie needs are less than the calculators suggest. I think that mixing things up helps with weight loss because a) you don't get diet fatigue b) your body may not decrease your metabolic rate c) you may subconsciously eat less on your non-indulgent days to a greater extent than its needed make up for the more indulgent days, and all this can add up to a slight improvement in speed of weight loss.

PhilT's suggestion makes perfect sense, so why not do that for a month and see how you go?

Hiya, maybe starvation mode is not a proper name for it but there definitely is a condition when if you don't eat enough calories you will not lose weight, even if those calories are half one's TDEE.
I was eating less than 1200 calories (usually around 1000) before I found out about 5:2 and I was losing nothing at all. As soon as I started 5:2 I also started to eat more (more than my TDEE, because I had the wrong number at first) and I also started losing weight, which was very impressing!
I would start with Phil's suggestion and see how it goes. If you have any additional questions, please don't hesitate to ask!