I Tried 5:2 Intermittent Fasting For A Month—Here’s How It Went

My natural hunger cues have always left me itching for something to nosh on every three or four hours, so when my Mom swapped her three-meals-a-day eating style for smaller, more frequent meals back in the early 2000s, I became a certified grazer, too.

On a typical day, I’d enjoy six mini-meals: I’d start the day with a Bulletproof coffee and a little Greek yogurt, munch on a protein bar and an apple mid-morning, go for a salad with chicken and veggies at lunch time, enjoy a slice of avocado or almond butter and banana toast mid-afternoon, have grilled chicken and sautéed spinach for dinner, and snack on an apple with peanut butter before bed.

In college, eating these smaller, more frequent meals helped me avoid the ‘Freshman 15,’ and later, at the office, it kept me focused on my work. Research has even linked a ‘grazing’ eating style with lower fasting insulin levels, and I’ve found it keeps my blood sugar and energy levels nice and stable.

After ditching my cubicle to go full-time freelance this January, though, my grazing basically transformed into non-stop inhalation of almond butter. Whether seven o’clock in the morning or nine o’clock at night, you’d find me in the kitchen with a spoon in one hand and a jar of Justin’s nut butter in the other. I was spooning my way through a jar of nut butter every three to four days, and it was time to kick the habit.

As a CrossFit® athlete and health and fitness journalist, I’m constantly charging after new goals, learning about trends, and reading up on the latest research—and I wondered if intermittent fasting, which I’d seen lots of buzz about, could help me nip my out-of-control grazing in the bud. Curious, I decided to give it a go for a month.

Intermittent fasting, which is basically the exact opposite of my grazing ways, is the practice of abstaining from food, typically for extended periods of time. Though fasting has roots in many religions, including Christian, Judaism, Hinduism, Buddhist, and Islam, it’s become popular in the wellness community in recent years for its weight loss and health benefits.

The thing with intermittent fasting: There’s no one right way to do it. Some approaches involve completely nixing food for two days per week, others involve eating only during a small six- to eight-hour window every day, and others involve eating just 500 calories a day two days per week.

Related: Is Intermittent Fasting Really All It’s Cracked Up To Be?

I usually eat between 2,200 and 2,400 calories a day, so going full days without any food did not appeal to me (how would I train?). I opted for a type of intermittent fasting known as 5:2 fasting.

Five days a week I’d eat as usual, but on two non-consecutive days, I’d limit myself to just 500 calories a day.

I still had hesitations: Could this approach help me overcome my nut butter habit? Would I be able to stick to it for a full month? Would it affect my workouts?

I hit up one of my favorite dietitians, Jessica Crandall, R.D, who’s a spokeswoman for the Academy of Nutrition and Dietetics, to talk through my concerns. “If you’re an athlete, you need to plan when you’re going to take a rest or recovery day, and match that up with when you’re going to fast,” she told me.fasting is going to help with recovery? She also advised me to pay close attention to how I felt on the lower-calorie days, and to look out for any nausea, lightheadedness, or cramping.

I followed Crandall’s advice and planned out my first week so I’d fast on Thursday (when I’d do yoga instead of CrossFit) and Sunday (when I’d take a full rest day). In week one, I ate normally Monday through Wednesday and made an effort not to over-indulge on Wednesday night in anticipation of Thursday.

Week 1, Fasting Day 1

I’ll just come right out and say it: My first low-calorie day was a total fail.

I started off okay, whipping up my usual Bulletproof coffee (coffee with MCT oil, butter, and collagen protein) in the morning and sitting down to work until lunch. I’d normally drink my brew (which clocks in at 185 calories) and down my first two mini-meals in that time, but knowing I needed to make my 500 calories last all day, I sucked it up and stuck with just the coffee.

And then noon rolled around… My belly’s excessive grumbling let me know my body was not happy about this switch in routine, so I opened the fridge, looked longingly at my PB, and grabbed a Granny smith apple (60 calories) instead, hoping the fiber would help keep me satiated a little while longer.

An hour later I was hungry again, and I’d already ‘used up’ more than half of my prescribed daily calories. I no longer wanted a scoop of peanut butter; I wanted a 32-ounce steak.

I compromised by grilling up some chicken (200 calories), and luckily felt satiated.

Things went truly awry a few hours later, however, smack in the middle of a downward dog at yoga. I felt lightheaded and unstable (which didn’t surprise me considering I’d consumed just 465 calories, as opposed to my usual 1,500 by this point), and needed to avoid any positions where my head went below my waist for the rest of class. I left feeling agitated.

So what did I do? Hit up my favorite healthy chain, Sweetgreen, and order my go-to: a beet and goat cheese salad with chicken. I tweaked my order and skipped goat cheese and dressing to save some calories, and though the meal tasted pretty flavorless, it still clocked in at around 500 calories. Oops.

That salad made me feel human again, but it pushed my total calorie intake to 965 calories—almost twice more than I was prescribed.

Week 1, Fasting Day 2

I woke up wildly hungry the day after my first attempted fast and housed a three-egg, turkey, cheese, and broccoli omelet, and two slices of buttered whole-grain toast for breakfast. My total calories for the day came in higher than usual, at around 2,500.

On Sunday, my second fasting day, I slept until eleven and opted for a large (like very, very large) black iced coffee and three eggs for breakfast (210 calories).

I hoped my late start would make the rest of the day easier, but by mid-afternoon my stomach was growling again. I tried the fiber approach again by snacking on some carrots (110 calories), and they held me over for another two hours. For dinner, I grilled up some more chicken (200 calories) and sliced up half an avocado (120 calories).

I definitely didn’t feel satisfied or well-fueled. I noticed I’d been responding to emails at a sluggish pace, and again, I caved. I made myself a piece of plain Ezekiel toast (80 calories) so I could power through my inbox, and hit the hay having once again exceeded my calorie limit. At least I was only 200 calories over this time?

Tweaking My Approach

Clearly, week one didn’t go well. My body seemed okay overall—my digestion was still regular and my weight hadn’t changed—but I just didn’t feel good. I spent my first fasting days constantly thinking about food and had to lower my usual squat weight by 10 pounds during Friday’s workout. On Saturday, my training partner also commented that I seemed to be moving slower than usual.

I called Crandall again, and she suggested I increase my calorie intake to 750 and up my protein on fasting days. “As an athlete, you don’t want to put yourself at risk for muscle loss or nutrient deficiencies,” she said. “so try eating egg whites for breakfast and even more lean proteins, like chicken or beef, throughout the day,” she said. I hoped the tweaks would be enough to power my workouts and not feel supremely miserable on lower-calorie days.

Weeks Two And Three

Luckily, my next two weeks went significantly smoother. My digestion continued as normal, and while I was still a little testy on my low-cal days, I got through it. The best part, though? I kept my peanut butter addiction under control throughout my five normal eating days and consistently ate between 750 and 800 calories on my fasting days, which felt much more manageable than trying to stick to 500. Following Crandall’s advice, I made sure the bulk of my fasting-day calories came from proteins. I also focused on high-antioxidant vegetables, which she said would help with satiety and muscle recovery.

I settled into a routine on fasting days that looked like this:

  • Breakfast: large black coffee, two eggs, one egg white (160 calories)
  • Snack: granny smith apple (60 calories)
  • Lunch: undressed spinach salad with half a pound of grilled chicken (240 calories)
  • Dinner: half a pound of grilled chicken or pork with sautéed kale (250 calories)
  • Snack: apple or serving of baby carrots (50 calories)

My biggest remaining issue: that my Monday and Friday workouts (which followed fasting days) still suffered. I felt strong for the first 25 to 40 minutes, but then petered out. When I rowed, my calories-per-hour dropped by about 200; when I ran, I tacked 20 seconds onto my mile time; and when I did burpees (which are usually my thing), I felt like I was moving through molasses. Crandall explained that this was probably due to low carb intake on my fasting days.

Making It Through The Month

After four weeks of fasting, I stepped on the scale to see that I’d dropped two pounds—and losing weight wasn’t even my goal. My body fat percentage didn’t change, though, so I speculate it was just water weight.

Ultimately, my experiment proved that consistently dropping my calories so low twice a week wouldn’t be doable long-term if I wanted to keep training hard. Even after I settled into my routine, I found myself feeling pretty cranky and obsessing over food on fasting days—and day-dreaming about brunch mid-squat!

I will say, though, that the plan definitely did help me kick my nut butter habit. Ditching the calorie-dense creamy stuff on my low-cal days helped me realize I didn’t need that much of it on the other days of the week, aside from my usual nut butter and apple snack—and that’s a win for me.

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