What happens if you Fast 5 Days and Walk 7 hours a day?

I wanted to see how much weight you could possibly lose in 5 days.

Recently, I ate 30 eggs a day for a month to “bulk.”

This was effective as I indeed became a lot bulkier. Along with the muscle I also gained a decent amount of fat. Then, I went to Belgium for the holidays and put on even more weight.

So, as a way to jump starting my weight loss, I wanted to see what is the most amount of fat I could possibly lose in 5 days? What I did was:
・Fast for 5 days
・Walk 7+ hours a day
・Cold exposure

Before picture

Over the 5 days I tracked my weight, mood, blood sugar, sleep, took several blood tests and I used a machine to check my muscle mass and body fat percentage. Here we’ll look at what exactly this fast did to my body, as well as do a deep dive into how fasting, exercise & cold exposure all synergize together as well as the debate over what “breaks” a fast.

Starting Weight

My starting weight was 84.9kg (187.2 lbs)

I finished my last bit of food on Saturday at 1PM and snapped a before picture (above). Right away, I needed to get moving. It being the first day of the fast, I really wasn’t expecting anything too difficult. 

I also did an InBody scan which is a Bioelectrical impedance analysis device designed to measure muscle mass, body fat and water content.

Starting Body Composition
・Soft Lean Mass: 70kg (154.3 lbs)
・Body Fat Mass: 9.9kg (21.8 lbs)
・Body Fat Percentage: 11.7%

Starting Blood Tests

Insulin 4.5mcU/ml
Inflammation (CRP) 0.25mg/dl
Longevity Marker (IGF-1) 194 ng/ml*
Autophagy Marker (WBC) 6720 /mcl*

*I will explain these properly in a moment.

Day 1

I finished my last meal by 1PM on January 7th. Last time I did a long fast, I finished my last meal at night, meaning I would break my fast at night. I much preferred an earlier start and an earlier finish to my fast.

My flat foot.

My friend’s foot.

I’m not actually the best person to be doing this challenge because I have flat feet - essentially the arches on my feet are collapsed so if I’m not careful, walking and running long distances can be really painful. (First picture is my flat foot, the second is my friend’s normally-arched foot). The first day I ended up walking 29,461 steps and was limping a bit by the end of the day but other than that it wasn’t too hard - surprisingly the hunger didn’t bother me much at all. 

The Growth versus Longevity Tradeoff

The annoying thing about being alive is that there’s this tradeoff between growth and longevity. Growth factors like human growth hormone and IGF1 help you grow muscles and lose fat, heal your wounds, regenerate your cells(R1,R2,R3,R4) and even grow new brain cells. However, studies on mice, worms and flies has found that decreasing these beneficial growth factors has them live 50% longer.(S1,R1) There are a number of people in Ecuador who have a genetic defect that makes these growth factors far less effective in them - unsurprisingly, they are much smaller than the average Ecuadorian, but they also are uniquely protected against diseases like cancer and diabetes despite having almost double the rate obesity. 

Fasting is known to decrease these growth factors like IGF-1 (R2,R3) and research out of California found that this temporary reduction of IGF-1 through fasting increases your stem cells ability to regenerate (S1,S2,R1) and strengthens the immune system.