FastDiet Update: Week 20

Fast DietToday I start week twenty of the FastDiet, also called the 5/2 Diet. In this post, back in March, I outlined my plan. I weighed myself about a week ago, and so far I’ve lost 21 pounds! I feel fantastic, and I’m wearing clothes that haven’t fit me in a decade.

I get a ton of questions about how I’m doing it, and the short answer is that I eat 500 calories two days a week, and whatever I want the other five days. But there’s a little more to it than that, so I wanted to give you an update about how well I’ve stuck to the plan I had outlined.

Fasting Days

The main part of my plan, eating 500 calories twice a week, I have not strayed from in any significant way. Once I went ten calories over, once I went ten calories under (I’m sure it’s been less exact than that, but I mean as far as I could tell). Twice, when I had a week of traveling coming up, I did three fasting days in one week and one the next week. Other than that, I’ve been consistent.

In the beginning I was waiting until noon to start eating on the fasting days, but after a few weeks I determined that it was actually easiest if I didn’t start eating until five or six in the evening. Sometimes around five I’ll have a snack, and then an hour or two later dinner. Sometimes I’ll just save it all for dinner.

Dinner is usually something frozen, just to make the calorie counting easier. Amy’s Burritos and Amy’s Pizzas get eaten a lot on those days. I love frozen food, so this isn’t any kind of compromise or sacrifice for me. I also often do pasta on the fasting days, either frozen or not. Ending a fasting day with a big bowl of carbs is very satisfying. Subway works great if I’m not home for dinner on fasting days (although I try to schedule them for days when I will be home).

I think the reason I like eating later is that I go to bed full and happy. By about ten in the morning I stop being hungry, and I just don’t think about food until dinner. The more busy I am, the easier it is.

I’ve read that some people start to like the fasting days, to look forward to them. I can’t say that I like them, but they are a bit of a relief. As in “Yay, I get to make up for all the mac and cheese and pizza I ate!”

Five Days A Week

I’d planned on giving myself twelve hours with no eating each day, in other words if I finished dinner at 8pm then I couldn’t eat until 8am. I still think this is a great idea, and most days it happens naturally because I don’t tend to snack after dinner anymore and usually make my breakfast after my kids are out the door. But it’s not something I consciously stick to. I would like to pay more attention to that again.

I’ve been very consistent about eating dessert with breakfast – not a difficult thing to stick to at all! :-) I’m reasonably sure at this point that this is helping me to not overeat later in the day, when I used to eat myself sick. The days when I’ve skipped my morning chocolate I’ve either eaten way too much for dinner or I’ve had a really late snack. Some of it could have been completely in my head – since I’m in on the experiment, that might have changed the outcome. But there were several times when I got to the end of the day, ate badly, and then remembered that I hadn’t had dessert that morning.

In the beginning my goal was to eat an apple and a salad every day. I still think this is a great idea, but I haven’t kept it up. Would I be losing weight faster if I did? Probably. I eat fruit with breakfast every morning and almost always have some fruit later in the day, but it’s not always an apple. But I’m very lazy about washing lettuce. The weeks when I’ve washed a bunch at the beginning of the week (or bought pre-washed) I’ve eaten a lot more salad. It’s just that easy. So I need to do that more.

Every Day

My goal was to get at least eight hours of sleep. While I haven’t done it every night, I’ve done it way more often than I had in the past. I can count on one hand the number of times I stayed up to two in the morning – that used to be a regular occurrence. When I’m not exhausted, I just make better choices generally – not just with food.

Another goal was to drink 40 ounces of water each day. I stopped keeping track of my water intake after a couple of months, because I developed a very good sense of how much I need. 40 ounces – or any number, really – is just arbitrary. I know how I feel when I’m hydrated, and I know how I feel when I’m not. It takes a different amount of water each day, and frankly, extra isn’t doing me any good. So I’m happy to say that I now drink as much as I need to, which wasn’t happening before.

I’m still taking Fucothin – three tablets three times a day (although sometimes I don’t get them all in on fasting days, since they’re supposed to be taken with food). It’s an expensive habit, but it’s worth noting that there’s a diminishing-returns thing going on: the more of them you take a day, the less the extra benefit is. You can take three pills a day and get 75% of the benefit as nine pills. The big question: is it working? I have no idea. It’s supposed to raise your metabolism. Like I’ve said in the past, I trust Dr. Oz, and being forty I’m sure my metabolism needs all the help in can get. Aside from cost, there are zero side effects, so I don’t see the harm in continuing.

My last goal when I started this was to really let myself get hungry before eating, and then stop when I’m full. I’m thrilled to say that I’m doing this just about all of the time now. I’m not sure why it’s been so easy, but I suspect that not eating much two days a week just makes me appreciate food more on the other days. I feel like I eat like a normal person now.

A lot of people have asked me how exercise plays into this. There were a couple of months towards the beginning where I was exercising quite a bit (for me, anyway), because I was getting ready for three 5K races. Most weeks I would go for a walk or run twice a week, and there were several weeks when I would do it four or five times a week. But for the past two months I’ve hardly exercised. I did a 5K six weeks ago, and that’s the last time I did purposeful exercise. I do a fair bit of walking and biking just living in NYC though, so I’m sure that helps.

I was definitely losing weight faster when I was exercising, which of course makes sense. But my point is, I’m still losing without exercise. What I weigh has always depended more on what I’m eating than if I’m exercising.

That doesn’t mean, though, that I don’t want to exercise. I feel better when I exercise, I’ve just been lazy. The next race I have coming up is a 10K in October, and that’s an important one: my time for that race will determine my starting corral for the Disney Princess Half Marathon in February, so I want to do really well. I’m going to try to get back on track before my training officially begins for that, running two or three miles a couple times a week. Totally do-able!

And of course, weight training is important. I have a good routine that I can do in my living room in about half an hour. I’d like to get back to doing that a couple times a week as well.

The last thing I want to say is that this is the easiest eating plan I’ve ever tried to stick to. Two months is usually my limit for any kind of diet, but I’m almost done with month five and I’m still going strong. The mental strength that you need for most diets – thinking about what you’re eating all day long, just about every day – is what usually does me in, not the actual food. Only having to think about this twice a week is what makes it easy.

Want to read more about the FastDiet? Here are all of my posts on it:

Diary Of A Faster, Day 1

A Great First Week On The FastDiet

FastDiet Update: A More Reasonable Loss

Another Pound Gone; Why Is The FastDiet So Easy?

Another 3 Pounds Gone: Doing The FastDiet While Sick

FastDiet Update: Week 20

Still On The Fence About The FastDiet? Here’s Some Motivation

Exercising And FastDiet Days

Originally posted on Selfish Mom. All opinions expressed on this website come straight from Amy unless otherwise noted. This post has a Compensation Level of 0. Please visit Amy’s Full Disclosure page for more information.


  1. Jessica says

    I have been doing a version of this for over a year now (did not know it was an actual diet!) and it works well for me. I am not a snacker – I would much rather have one big meal a day than a bunch of small ones. It seems most diet plans fight my natural tendency to eat very little most of the day and then have a nice full meal. I am happy to see that I am not the only one. I think I will eat this way for the rest of my life.
    Way to go with your successful weight loss Amy!

    • says

      @Jessica: So happy to hear from someone who’s been doing something similar for so long! I was definitely a snacker, but it was just mindless eating. When I’ve tried to follow the (completely unfounded) advice of eating a bunch of small meals a day, I’ve just ended up unsatisfied and obsessed with food.

  2. says

    Following your lead, I began this diet on Monday. So I can’t really say yet if it’s worked – -but I can say that it makes so much sense to me. Diets that everyone loves, and that experts always say are the best, seem to me to make you think about food all the time. On this diet, i only have to think about it – really think about it – twice a week. That I can do. And it also just seems like that way thin people eat. Not a diet. Just a way of eating. Hopefully, I will lose the 10 pounds I’m hoping for, and then just keep eating this way to maintain. Thanks for the inspiration!

    • says

      @Nancy: So glad you’re on board! If you have ANY questions or need support, please don’t hesitate to reach out. And remember: the first couple weeks are the hardest. Get through those, it gets MUCH easier.

      I had to work on not thinking about it the other five days – in the beginning I would kind-of ruin my five eating days going “Ugh, can’t eat tomorrow…” Once I got that under control it was really great mentally.

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