I have tried both protocols: I posted an introduction of Carb Nite and a follow-up on my experience here and here. The potato hack I only started recently and I just finished another hack the day before I wrote this post. It's time for a face-off.
Dietary prep: None really. But it helps if you 're used to the paleo diet already.
Cycle duration: There is no standard timing. Some people do the hack for 1-21 days whenever they hit a plateau. I decided to do 2 days per month and the remaining 28 days of the month I'd be on my normal primal diet
How to Potato Hack: Every batch of potatoes must be peeled, cooked and then cooled in the fridge to increase their resistant starch content. Then they can be reheated and prepared as you like as long as they are very low in fat (1 tsp/ 700 g of potatoes). You aim to eat 1.4 to 2 kg of potatoes per day.
Workout: It's recommended to go easy during the days you potato hack. So schedule it on a de-loading week or a rest day. Once you're on your normal paleo diet again you can work out as usual.
Why it works: According to Denise Minger, the author of Death By Food Pyramid, the metabolism of the body changes once we either go very low fat (under 10% calories from fat) or very high fat (over 65% calories from fat). This causes increased insulin sensitivity and glucose tolerance causing the body to store fewer carbs as fat. Resistance starch-rich potatoes are lower in calories and keep us more sated for longer. Resistant starch also has a therapeutic effect on the gut which counters sugar cravings in the future.
Dietary prep: A dialled in paleo diet + 10 days of being super-low on carbs. Do not exceed 30 g of sugar and starches per day.
Cycle duration: On the evening of your 10th low-carb day you do your first Carb Nite. The following cycles are 7 days of very low carbs, again under 30 g per day, with your Carb Nite scheduled on the 7th day.
How to Carb Nite: Start eating high carb foods around 5 pm, and keep snacking high-carb foods until dinner time which also should be high in carbs like potatoes or rice. Follow up with a dessert, and have another snack before bed.
The first carb meal must be low in fat. As the day progresses the more fat you can add.
Workout: During the entire cycle you should only do easy workouts like walks and simple power lifting except on the day you have scheduled your Carb Nite. The workout on that day should be harder and depleting.
Why it works: Starving the body of carbs for one week causes the body to become ketogenic and more insulin sensitive. When ketogenic your body's main energy source is fat either coming from food your body's fat storage. Once an evening of sugary stuff follows the body reacts with strong insulin spikes which cause a short-term metabolic reset which allows the body to burn more fat.
There is no risk of wanting to extend the carb-refeed part of the potato hack because it is not the pleasant part. The psychological setup here is almost the opposite of Carb Nite: you can't wait to get over the carb-refeed and eat normal paleo again. Overfeeding on fairly plain potatoes is not easy. The reason why I decided to do only two days of potato hacking was that I could easily fit it into my schedule and I could endure two days of mono-dieting. Although eating resistant starch potatoes does cause a moderate insulin spike the fasting glucose levels on the next day stay relatively low which is good for your body's health and will not cause a sugar whiplash on your metabolism.
My experience with the potato hack was much more gentle. The first day I needed to get used to the blandness of just eating potato and was very much looking forward to eating other real foods again. The energy level was moderate, but I never felt exhausted. After having completed my two-day potato hack, I never felt sugar cravings when I returned to eating normal paleo again. Weight loss never occurred during the hacks but always after, on average a drop 200-300 grams every day for the next following five to seven days.
You might have guessed already that from my own experience, I prefer to do a short potato hack from 2-3 days once a month instead of a Carb Nite once a week. The potato hack is less constricting and can be customized to one's needs. You only need to adhere to a few rules. Carb Nite is more suitable for people who do well on a strict protocol and are motivated by a big binge reward, having the cake and eating it all.
Have you tried any of tried any of these protocols? What do you think? Would you do it again?