Go without a coat when it’s cold; find out what cold is. Go hungry; keep your existence lean. Wear away the fat, get down to the lean tissue and see what it’s all about. The only time you define your character is when you go without. In times of hardship, you find out what you’re made of and what you’re capable of. If you’re never tested, you’ll never define your character.
Henry Rollins
The disclaimer first: As usual, no warranty. This is something you should only do if you know your body, what it can take, and how it will react. And you should check with your physician whether this is a good idea. Prolonged fasting can be highly dangerous and potentially fatal.
After visiting my mother for xmas, I thought it was a good idea to do a little fasting. First, she is a really good cook. Second, I am slightly overweight (age-adapted BMI says it’s normal weight, but yeah, no). Third, a cleanse at the end of the year sounded like a good idea. And fourth, it is
interesting to see what you can do without — for a while.
I went home on the 25th of December and there were seven days left until the new year, so I decided on a seven day fasting period. The fast consisted of only water, tea and black coffee, but with magnesium-calcium and omega 3 supplements in the evening. I also took some Himalayan salt for electrolytes. These supplements should not break the fast and help with muscle cramps and fatigue.
As written in the disclaimer, this is something that should be done carefully if at all. Seven days of fasting can easily become unhealthy or fatal. Personally, I know my body and have already done multiple three-day fasts. I also usually eat only once a day (intermittent fasting), so hunger pangs are just that, information that the body craves food, not a command.
I also asked ChatGPT for a prediction of what would happen on each day (BE = body effects, Pos/Neg = positive/negative effects):
Dec 25 Fasting Day 1/7
BE: Blood sugar levels drop; glycogen stores start depleting; slight hunger and mild irritability.
Pos: Starting detox; reduced calorie intake; initial fat-burning begins (lipolysis); insulin sensitivity improves.
Neg: Hunger pangs, headaches, fatigue, irritability, stomach grumbling.
Tips: Stay hydrated, drink herbal teas, avoid intense physical activity, keep busy.Dec 26 Fasting Day 2/7
BE: Glycogen stores fully deplete; ketosis begins; body starts burning fat for energy; mild energy dip.
Pos: Mental clarity begins to improve; fat loss starts; reduction in inflammation begins.
Neg: Headache, fatigue, lightheadedness, weakness, nausea, bad breath (ketosis breath).
Tips: Rest as needed, add salt to water or drink electrolyte-rich fluids, chew sugar-free gum.Dec 27 Fasting Day 3/7
BE: Ketosis is fully underway; metabolic adjustment occurs; reduced appetite; enhanced mental clarity starts.
Pos: Energy levels stabilize slightly; improved focus; reduced inflammation; cellular repair begins (autophagy).
Neg: Bad breath, feeling cold, muscle cramps, insomnia.
Tips: Use mouthwash or sugar-free gum, wear warm clothing, stretch gently for cramps, meditate.Dec 28 Fasting Day 4/7
BE: Body adapts to fasting; cellular repair intensifies; autophagy peaks; digestive rest is evident.
Pos: Improved energy, reduced cravings, enhanced focus; anti-aging and immune-boosting benefits begin.
Neg: Cold hands/feet, difficulty sleeping, mood swings, slower bowel movements, slight fatigue.
Tips: Stay warm, practice deep breathing or meditation, engage in light creative activities or walks.Dec 29 Fasting Day 5/7
BE: High autophagy; glycogen stores nearly empty; body burns fat efficiently; hormonal balance improves.
Pos: Heightened mental clarity, reduced cravings, continued cellular repair; anti-inflammatory effects.
Neg: Mood swings, mild dizziness, potential dehydration.
Tips: Rise slowly to avoid dizziness, take it easy, hydrate, focus on light mental tasks.Dec 30 Fasting Day 6/7
BE: Deeper cellular cleaning; peak autophagy; enhanced skin clarity; fat is primary energy source.
Pos: Boosted immune system; anti-aging benefits; sharper mental focus and energy.
Neg: Emotional sensitivity, potential muscle weakness, reduced stamina.
Tips: Journaling for emotions, plan minimal physical tasks, continue hydration and light stretching.Dec 31 Fasting Day 7/7
BE: Hormonal balance peaks; fat stores are primary energy source; detox is nearly complete.
Pos: Sense of achievement; maximum fasting benefits (anti-inflammatory effects, immune system reset).
Neg: Hunger pangs return, mental fatigue late in the day, low energy.
Tips: Reflect on achievement, avoid overeating, plan a light meal to break fast gently.Jan 1 Breaking Fast
BE: Refeeding phase begins; digestion resumes; nutrient absorption is heightened.
Pos: Improved digestion and mental clarity persist; feeling of renewal.
Neg: Overeating risk, digestive discomfort if fast is broken improperly.
Tips: Start with light foods like soups or smoothies; eat slowly and avoid heavy meals immediately.ChatGPT
It also gave me criteria for when to stop fasting: persistent dizziness/fainting, nausea/vomiting, heart problems, or extreme weakness that does not improve with rest. Yeah, no shit, but still a good reminder.
Overall, the fast went okay’ish.
The hunger pangs were annoying on day two and day three, but were very muted afterwards. As they come in waves, similar with addictions. You just have to ride them for 15 to 25 minutes, so distraction is key. You can also put some salt under your tongue (ChatGPT tip), which apparently reduces the hunger.
I stopped doing exercise after day two, due to lack of energy and likely problems with recovery when not eating. Sports and fasting do not seem to me like a great combination.
The overall lack of energy was not that much of a problem between the years, as I spend most of the time at the computer going through stuff and watching movies/series. From day three or four onwards with a bit more clothing, as the body felt cold, esp. the hands and feet.
Hydration was important and taking each day separately did help. Looking at the ChatGPT predictions did provide me with some information on what to expect that day.
Looking back, was it worth it?
On the health side, I don’t know. According to ChatGPT and other sources, it should have led to cellular renewal (autophagy), ketosis, digestive reset, and hormonal optimization. Personally, I think the reset was useful. I did lose some weight, although most of that is likely water and will get back once I have eaten regularly (i.e., once a day as usual). Still, I feel good.
On the mental health side, it was interesting to see that I can extend my fasting period from three to seven days. It’s not something I would do during the year, but it fits very well at the end of the year. Given that I want to change my diet long-term, it should have reduced cravings for the food I ate before the fast. Day seven felt a bit like a blank slate — and I did not crave junk anymore. Not sure whether that will hold and it’s rather questionable that it can form new habits. Given that it is the time between the years, the environment is different. The same triggers that I did not face during that time (e.g., shops near work) will likely still trigger the same cravings when back at work. But it’s a start and we will see.
ChatGPT also gave tips for the refeeding phase that were very helpful. Due to the lack of food, the stomach contracts, so you have to slowly reintroduce food. That means small portions (ideally bone broth or soup), small bites, chewing thoroughly, and soft fatty meats or fish. It might take a few days until the portion sizes can be normal, well, normal for the post-fast eating habits.
So, overall the experience was positive and provided a nice, clean start into the new year.
If you want to do something similar, I’d encourage you to do it deliberately and very carefully, use days with little activity (e.g., the time between the years), and get medical clearance. People differ vastly in how their bodies react and I was already used to fasting. If I hadn’t been, I’d probably start with a three-day fast. That would be hard and rewarding enough. Especially as it will suck — for a while. Both physically and mentally. But it might also be worth it.
And no matter how you got into it, Happy New Year. 🙂