Cheating on Keto: Why It's a Decision, Not a Failure, and How to Do It Smart

2019-04-24

In this recording

A 17-minute recording from my backyard in spring 2019, answering a question from my Facebook group: someone a few days in drove past a Dairy Queen and asked what the deal was with cheating. Weed whackers run in the background for much of it.

[0:00] The question: is keto 24/7, or can you have cake once in a while? My first answer: extra calories hold you back on any diet, keto or not.
[0:49] Ketosis isn't the goal. It makes a calorie deficit easier because you're less hungry, but I said the metabolic edge on its own isn't big enough to talk about. Hunger hormones and blood glucose are the lever.
[1:38] Your diet is what you eat habitually. Two pieces of cake in a year aren't part of your diet. Cake and six beers every Friday are.
[2:24] Cheating weekly or more often will hurt weight loss and metabolic flexibility and will knock you out of ketosis.
[2:59] Smart cheat number one: stay keto but eat at maintenance for a day or two. Ribeye with butter, more cheese, pork rinds and dip. Then go back to your deficit.
[3:44] Smart cheat number two: eat off plan but keep the day's calories in a deficit. My reasoning was that refilling glycogen is the disruptive part, and you can't refill it while you're under your calories.
[4:57] What a single cupcake probably does: you feel sluggish and get cravings. That's where the real damage is, if it lowers your activity or sets off more eating.
[5:40] The gut side. I described the digestive tract as a tube your body keeps "outside" itself, with bacteria that adjust to what you feed them. After a long stretch of low carb, a big carb load can mean gas, constipation or diarrhea.
[7:37] I don't like the word cheating. If you decide to eat a cupcake, that's a decision. Grandma's 80th birthday carrot cake is a good decision. Have a lower-calorie day and eat the cake.
[8:15] Psyllium husk helps with the gut side. Capsules are small, which is why I'd tell people to take about ten.
[8:55] A stretch about my coaching and my Facebook group. This post skips it.
[12:28] A garden tour: blueberry bushes, and an eastern redbud I'd transplanted. I ate a few of its flowers on camera and said they taste like broccoli.
[16:06] Close: eat the wedding cake at important family events, maybe make it a low-calorie day, maybe add psyllium.

Watching this in 2026

The best thing in this recording is the reframe at [7:37]. "Cheating" puts you on trial for a cupcake. "Decision" asks whether the cupcake was worth it to you. I said the same thing nine months later in a shorter clip about getting back into ketosis: make decisions, not mistakes (live IMG_0993). And in 2017 I'd already told people not to save up carbs for potato chips but to spend them on vegetables (video 1vyxuWlxT5M). So this idea goes back a long way.

The part I'd tighten is the glycogen arithmetic. I put total glycogen at around 700 grams, or about 2,800 calories, and built the second cheat strategy on it. That number isn't on the evidence pages, so read it as my 2019 estimate. The strategy doesn't depend on the exact figure, though. A cupcake inside a deficit day is a small, short disruption. A 4,500-calorie nacho day is a much bigger one.

The pitch in the middle is a coaching offer, so this post leaves it out. The redbud flowers were me eating off a tree to make a point. Don't take it as foraging advice: know what a plant is before you eat it.

The claim worth unpacking: "ketosis isn't the goal"

This is the line from [0:49] that I'd stand behind hardest today. The metabolic-ward studies tested it directly.

In Hall et al., 2015, 19 adults on a metabolic ward lost 53 ± 6 g/day of body fat with carbohydrate restriction versus 89 ± 6 g/day with fat restriction at the same calorie cut.
In Hall et al., 2016, 17 men switched to a ketogenic diet at the same calories. Energy expenditure went up about 57 kcal/day, and body-fat loss slowed after the switch.
Over a year in the free-living DIETFITS trial, healthy low-fat lost 5.3 kg and healthy low-carb lost 6.0 kg. The difference wasn't significant. (Its low-carb arm was moderate, not ketogenic.)

So the literature lines up with what I said. Ketosis isn't a fat-burning trick. If keto works for you, it's because you can stick to the deficit, which I covered in more depth in why keto works. That's also why cheating hurts more by setting off cravings and extra eating than by "breaking ketosis".

The gut explanation is half supported. Ang et al., 2020 found that a ketogenic diet shifted the gut microbiome, including lower bifidobacteria. That fits my point that your gut bacteria adjust to low carb. No study on the evidence pages tests what happens when a keto-adapted person suddenly eats a big carb meal, so the gas-and-diarrhea part is my experience and the group's, not a measured result.

Psyllium is a viscous, soluble fiber. In a review of trials, more viscous fibers reduced appetite in 59% of comparisons versus 14% for less viscous ones (Wanders 2011). That's about appetite, though, not about digestion after a carb day. Psyllium for a post-cake stomach is something I recommended, not something those trials tested.

Who should treat "cheat days" differently

Eating-disorder history: a restrict–binge–compensate cycle is exactly what to avoid. Plan special-occasion food with your care team, not a Facebook thread. See keto and eating-disorder history.
Diabetes medication: a big carb day affects blood glucose, so ask your doctor how to handle planned exceptions, especially if you're on insulin or other glucose-lowering drugs.

Key points

Your diet is what you eat habitually. A planned exception isn't your diet.
Call it a decision, not a cheat. Celebrations are a good reason.
Two smarter options: stay keto at maintenance for a day or two, or eat off plan inside a calorie deficit.
Ketosis gives no meaningful fat-loss edge at equal calories (Hall 2015, Hall 2016). Adherence is the edge.
Expect cravings, sluggishness and possibly GI upset after a big carb meal. Psyllium was my suggestion for the last one.