1958 So What. Has 1lb of fat changed composition since then? They burn it in a lab it is 3,500 then and now. How do they calculate kcal in food? They burn them. So same measure.
Note he doesn't state that the calculation for kcal in food is wrong because we eat them not burn them. Odd that.
He uses Mifflin St Joer to calculate the calorie burn, which is only an estimation, as we are all different. I prefer Harris Benedict it works better for me. But he only gives a start and end calorie deficit, it needs to be calculated for every new weight. His model worked out about 4000kcal per lb of fat. But that is using the average of the start end deficits. But we lose more at the start (the clever man says so). So the average deficit would be less than that. Reducing the actual kcal per lb of fat to roughly 3927 based on 1/3 at the higher rate and 2/3 at the lower rate.
I wouldn't give him a PHD for that.
Of course its complicated, we are all different and some burn more some burn less.
I wonder how long the steady state calculations were done to create a bespoke RMR for the participants of the study where they maintained weight in a lab for say 6-months. I suspect this didn't happen and the first assumption is they fit the Mifflin or Harris models perfectly.
I'll give him a A overall for his report. Assuming it is an A-level project.
Some clever bloke says the 3500 calorie per lb of fat rule is wrong. But then goes on to say it is broadly right for burning it in a lab. Either wrong or broadly right but not both.
He has constructed a much better model than Harris Benedict Or Miflin StJoer presumably. Well if you follow the link the model is Miflin StJoer but it only calculates the figures at the start (when you weigh lots) and thus as you lose weight the apparent deficit contributing towards the loss will reduce.
So for me it gives a maintain of 3,256, a diet of 1,813, and an end of diet maintain of 3,009. (3256+3009)/2=3132 for the average kcal burn.
Subtract 1813 of 3132 = 1319 per day deficit for a 90 day period to lose 29lbs.
Well that works out at 4095/lb of fat. Or a difference if 4lb over the 90 days.
But he states that you lose weight faster at the start so just averaging the start and end calorie burns will give a figure that is too high. So the actual calorie deficit will be less than 1319 per day averaged across the period. This will bring his result closer to the 3500kcal per lb of fat.
So he uses Miflins calorie burn model but adjusts the deficit for the duration compared to the 3500kcal estimate. So what, we are all different. He also doesn't mention that the calorie burn should be recalculate daily as you lose weight (which my excel tracker does).
And the difference from 3500 to his figure. Is probably within the margin of error of the Miflin model which differs from Harris Benedict (maybe mifflin was wrong and Harris was better), the calculations of kcal in food (which aren't exact anyway), and the calculation of exercise loading.
So he doesn't like the method to calculate 3500 kcal in 1lb of fat, as they just burn it in lab. Well guess how they calculate the kcal in food?
He does make some valid points. It gets harder later, the last albs os tougher than the 1st etc. Yep common sense. He also uses some very long term timelines. We all know adaption takes place in running, cycling and swimming. We get more efficient (a better runner, a better cyclist, a better swimmer). We therefore do the same stuff more efficiently which burns less calories. We are human our bodies are lazy. So if you walk 5-miles/day at the start of the study and the end the calories burnt will be less partly because you weight less but also because you have adapted.
Oh and the longer the diet goes on the more lax you will become unless you have the will power of the captain of the will power team from will power university.
He's not wrong but don't think there is much to say he is more right than before.
Effectively you need to eat at least your Resting Metabolic Rate to avoid starvation mode. Then calculate your activity burn rate. In theory with no extra exercise this is the most you can lose per day in kcal. But factoring exercise can allow a much greater loss.
However these are all average calculated from a study group. We are all different.
If I track all exercise, count all calories, calculate RMR and an allow an activity rating of 2 I still end up losing weight faster than the model predicts. Typically 250-300kcal per day difference. I have dieted continuously for 4-months tracking everything and losing 3-stone, plus other shorter periods. I always lose more than expected.
Conclusion. One of the following is true:
my activity is higher than I credit myself
training burns more than I thought
or my RMR is higher than average.
I err towards the latter as the most likely, lucky me.
There are some things that can influence your overall BMR most likely around times you eat, food types etc.
There is also a fat to energy transport mechanism that works both ways and is different for us all. Therefore some will find it easier to get fat, but will also find it easier to get thin.
(Note: I used to work with a larger lady. She always said wasn't I doing well on my diet. I said I was. She said great, but you do reward yourself as well don't you. What like 'I haven't eaten for ten minutes, well done me, I'll have a cake'. No. Guess why I'm doing well).
Losing weight requires a deficit of 3500kcal for every 1lb of fat you want to lose. Simples
Jedi - hope you are still training! I don't post much a the moment but this thread struck a chord.
I have lost weight before (19.5 to 14 stone12) and put on again a few times. Three Ironmans, 20+marathons and ultras etc. So I know what it is like to train fat and thinner.
It also sounds you are a typical weak willed goal orientated person (I am) and find black/white rules (no cake) for food easier to cope with than grey ones (some cake is OK).
Now for some hard truths. This isn't a diet. This is your new life. If you see it as a 'diet' then it infers that the diet will stop at some point and you will revert to being a fat bugger. I stayed sub 16 stone for 3-years but currently I am being a fat bugger - it is a personal choice.
1000 kcal deficit/day, which given your training you should be easily achieving if you are only eating 1800, is 7000 kcal/week. A lb of fat is 3500 kcal so you should be seeing a consistent 2lb/week drop. This may not always be visible on the scales due to body changes. (If I did a 20-mile run Monday night then I was 2lb lighter in the morning but back to normal the next day etc). But 2lb/week is easily achievable. So 8.5lb per months is easily doable.
Now the 2lb a week loss is designed for normal people. You (and me) aren't a normal weight and can sustain a greater weight loss for a longer period of time.
3/lb per week is 10,500kcal = is a 1500kcal per day deficit. With exercise you should be able to eat 2000kcal/day and burn in excess of 3500kcal.
If you were a lightweight female (lower basal metabolic rate than male) and burning 1500 kcal per day and sedentary then a deficit of 1500kcal per day is starvation and not good for you.
Given your size you should be aiming to eat at least 1800kcal per day and probably 2000kcal per day. Be truthful with exercise and on big training days a little more is important to keep the engine running.
Running will burn more calories than cycling so should help a lot. Keep building the run mileage.
But the advice is simple:
Be truthful with the eating, the exercise calories, and the tracking of data. There are no short term rewards (like cake). Every day there is a deficit it builds towards the next 3500kcal deficit and 1lb loss.
If you want to play rugby then yes pre-season training will be great. If you don't want to play again then the jury is out.
It may tempt you to play again, or be a substitute on the odd occasion which has increased injury risks.
It may be a good motivation and lots of fun so it has its merits.
Shouldn't be any major knocks pre-season if done right - it should be fitness and skills based. No need to increase the battering players get over the season. Can never rule out a twist or a bang though.
You will get more sport specific training through running, cycling and swimming.
At the start I found continuos running hard rather than the stop/start of rugby.
I'll leave you with just one question?
Are you an ex-rugby player?
Drop the ex- for the alternative. It is a tough question to answer. My decision was made the third time I displaced 3-vertabrae in my back in one season.