I have steadily been losing weight since Summer 2014, where I weighed roughly 107 kg.

Yesterday, I hit another milestone: 85 kg on the scale. (85.8 kg to be exact, but who cares about decimals right?).

My weight in 2017 and 2018 was hovering, on average, around 95 kg and I was not progressing down on the scale.

In late October 2018, with the scale still showing 95 kg, I decided to try something new: Intermittent fasting.

Specifically, I skipped breakfast and lunch once a week.

Mondays were designated as the fasting day. where I only consumed water and coffee until about 16:00.

The effects were immediate! I quickly lost a few kilograms of weight, with early December showing 93 kg - loss of 2 kg.

With Christmas and new years eve out of the way, 1. January 2019 the scale showed a weight of 94.7 kg.

I decided for a simple weight loss scheme based upon intermittent fasting:

1. I would track my weight every day, using google sheets
   • Easy: this I already do.
2. I would set a weekly target of 500 g weight loss.
   • Hard: with an average of 60 g / week the last four years, I believed this was very optimistic.
3. I would cut down on cardio, and do weight lifting instead.
   • 2/3 weight lifting, 1/3 cardio (exercise bike)
4. I would skip breakfast and lunch every time my daily target was not met
   • Easy: tracking my daily weight + my target weight every day made this a breeze.

Using the scheme above I lost 6.8 kg of weight in three months translating to 566 g / week!

In addition - due to the weight lifting I gained muscle! I plan to follow the same scheme until hitting 80 kg of body weight.

All in all:

I have tracked my daily weight and exercise since 2016. The primary motivation: I wanted to loss a bit of body mass and to do so it would be beneficial to track my progress.

The secondary motivation: I want to statistically calculate if my weight loss is primary due to exercising. This was my initial hypothesis since my weight fell dramatically after I began my exercising. Alas I could not keep the fast decline after a few months, and my new hypothesis is that exercise not the primary factor for weight loss in my case.

This also makes perfect sense, since it is very easy to eat too much during the day which is near to impossible to burn in the evening with the one-two hours of spare time. What does the data say?

For each day since 2016 I have an entry of current weight (measured in the morning) + how much exercise I got for the day. Typically, this is how much I rode my training bike in the evening. My initial hypothesis was that more exercise leads to more weight loss, but not necessarily the day after, i.e. training for 60 min one does not result in weight loss the next day but a few days after.

To simplify my data-set I summed all the daily values into weekly values and converted the weight into a weight changes, i.e. the delta between the first measure weight next week minus the weight on the first day of the week. My hypothesis was that there was a negative co-variance between exercise time and weight change, i.e. negative weight change with increasing exercise time.

[caption id=“attachment_1581” align=“alignnone” width=“743”] Scatter plot showing the correlation[/caption]

As seen on the scatter plot, there is indeed a correlation between between exercise time (x-axis) and weight change (y-axis) and it is negative. It is far from perfect though, at does not explain that much. CORREL states that exercise time explains only 30% of the weight change, so 70% of the weight change is not explained by the data that I have collected.

Looking at the data it is clear that increasing exercise helps with weight loss. Getting 100-150 min of exercise during a week seems to be a reasonable choice to maximize weight loss. Beyond this the weight loss decreases in magnitude which I cannot explain.

Getting less than 50 min but more than 0 min of exercise every weeks clearly shows a negative weight loss trend, while getting 0 min of exercise shows a smaller weight gain.

Conclusion: it is important to exercise at-least 120 min a week while keeping in mind that exercise is not the primary factor for weight loss (only 30%).

I made a decision to lose some weight exactly one year ago. This was prompted after a one week vacation with too much to eat and too much to drink and the weight telling me that my mass had increased close to 107.5kg!

107.5kg is waaay to much for my measly 189cm height, with a BMI of around 30 I was considered obese and not just overweight. I made a decisions to 1. eat less and 2. get more exercise. My goal was to reach 95kg in one year time.

One year has passed and I nearly made it there. My weight is now 96kg and my BMI has dropped from 30 to 26.9, which is still overweight but not considered obese.

Great Success.

For motivation and for sciency purposes, I decided to weigh myself every single day and record how much I exercised. Google sheets was perfect for this since I could easily input my weight and exercise minutes from my phone in the morning. Weighing was always done right after I left the bed in the morning.

As seen, weight-loss motivation was very high from August until start December. Then Christmas came and the temptations started. But I quickly got back on track with a decent amount of weight loss.

I did not fully reach my 95kg goal, partly because summer vacation resulted in 1 week with eating and drinking, as seen in the end of the graph where my weight spiked.

Regarding exercise, I mostly used my traning bike + a bit of running. On average, I exercised 14min a day according to my data, with a total of 86 hours! Not bad for a beginner!

My total weight loss is 11.5kg close to one kg each month about 30g/day. My next target is 90kg, i.e. 6kg weight loss. With 30g/day I expect to reach this in about half a year / end of january

Stay tuned!