My weight had climbed to 263 pounds (18 stone 11, or 119 kg). I had only tried dieting once, and remembered feeling crazy hungry all the time when I was dieting. I am a male in his mid-forties.

When I saw the BBC documentary, I started to dream of making long-term permanent changes. I made the following changes:
1) Making the commitment that following a diet and exercise plan was my primary commitment in my life, ahead of all my other responsibilities, i.e. it is more important than my wife, my children, and my job. They will love me more if I am healthy, happy with myself, etc. So don’t hesitate to put fitness first.
2) Committing to daily tracking of calories and exercise.
3) Committing to a 5:2 or similar diet plan.
4) Committing to limits on non-fast days. This has ended up being 2900 kCal on non-fast days.
5) Daily exercise (either 60 minute walk or a ~35 min exercise workout).
6) Adoption of habits that were shown to be common for people who have succeeded at long-term weight loss: accountability, eating breakfast, 1 hour of exercise per day, eating healthy. I am in this for the long-term.
7) Specific dietary changes:
a) Breakfast: No food or drink that contains processed sugars. No fruit juice. Fruit or nuts ok. Unsweetened granola ok. Dairy ok.
a) Eat a healthy hot lunch every day except fast days: No red meat, no white bread, no starches, have a double serving of vegetables, no dessert.
b) Eat healthier at home: No processed sugar (except birthdays), no desserts, no pastries, no processed food snacks, instead eat fruit and nuts. Complain politely if there are not enough vegetables at dinner.

Since I was making a large number of changes all at once, I decided to make a spread sheet so that I was approaching these changes in the most rational way possible. My goal was to

a) make a daily log. (I use MyFitnessPal to collect daily data which is then transfered to the log). When I started doing exercises at the end of August (I use the YAYOG [you are your own gym] iPhone app) it was too much strain on my body, so I decided to go to 6:2 and an 8 day cycle to give my body a little more time to recover from the workouts. Ideally, I do: Day1: Fast and long walk, Day 2:Feed and calisthenics, Day 3: Feed and calisthenics, Day 4: Feed and long walk. That way I have food coming in for at least two days after a work-out to help my body recover.

b) check my weight loss rate vs. RMR calculations so that I could monitor from week-to-week any metabolic slowing. One big question is to what extent my RMR at a given weight is suppressed due to the fact that I have lost weight. In other words, is my RMR smaller at 230 pounds than it would be if I had never been overweight? I looked around the scientific literature for a while and decided that Johannsen, et al, “Metabolic Slowing with Massive Weight Loss despite Preservation of Fat-Free Mass”, Journal of Clinical Enocrinology and Metabolism, July 2012, Vol. 97, pp 2489-2496 would give me a rough estimate about how my RMR would be (permanently?) penalised compared to someone who had never been overweight. This showed a 500 kCal/day RMR penalty for people who undergo massive weight loss. So the second leaf of my spread-sheet tries to track how my weight loss rate is related to RMR. I think there is some evidence of an RMR impairment, though I want to be more diligent recording exercise in order to be able to demonstrate that.

c) Aim for a level of fitness that minimizes my mortality rate. I decided to augment the BMI measurement with the ABSI, a measurement that includes height, weight, and waist measurement. For my height, this gives a weight of 180 lbs and a 34 inch waist. This allows me to aim over the long term for a weight and waist measurement is correlated to the smallest risk of mortality. This is the third page of my spreadsheet. I know that correlation is not causality, but I am betting that my chance of dying will be lower if I am fit and have specific fitness targets.

d) Try to predict how long it will take to hit 5 pound weight loss milestones. I want to estimate the date of the projected milestones based on RMR calculations so that I don’t have irrational responses to temporary weight gain or get impatient with the current loss rate. The idea is that given a particular Activity Factor (I am using 1.4—My calories burned per day are RMR*1.4 under that assumption— I can calculate the predicted date of the next milestone based on my RMR and additionally, the predicted date based on my estimated impaired RMR [see b)]. If my weight gets stuck at a particular point, I will be able to quantify the metabolic RMR impairment for that. In particular, the impaired RMR model says I won’t get below 210 pounds at my calorie consumption at 1.4 activity factor, but the non-impaired RMR would let me go under 180 pounds! That is a huge difference in possible ranges of results. I am very curious to see how that ends up working out. At that point, will it be wise to further reduce my calorie intake??

I thought it could potentially be useful to share this spreadsheet to those who may be interested in doing this level of management of their diet and exercise path. See the link to a Numbers-formatted spreadsheet that I have posted on my Dropbox account. I find the spreadsheet takes the worry out of the process because I can predict the future, better monitor my own feelings when I am tempted to overeat or not exercise, better understand the role my metabolism is playing in all of this, etc. I also get a nice boost from looking at the plot from time-to-time. I think that the long-term metabolic effects are going to be key.

https://www.dropbox.com/s/o57djlu4pznqgof/weight%20loss%20and%20fitness%20journal.numbers