How can a person who is 160 KG and 180 CM tall change into a healthy person who weighs 75~80 KG? How can one plan for this? Jogging is not possible because he has a leg injury and spine problem at L3 L5. Is "jogging/walking" in swimming pool okay? Water can help support his body weight.
I do not see this question as duplicate because this person is very stubborn and has a lack of determination, normal methods of weight-loss will not likely work.
TL/DR: Any sport (and swimming is an excellent one) will work, if done consistently, with applied hard effort and together with healthy diet and caloric deficit. No way to do it without clear goals and determination. To lose 80kg of mostly body fat, one would need 2 years focused effort, at least. It could be the one of the hardest yet most rewarding journeys one could take. Such that will not only improve the health but likely also self-esteem, general lifestyle, lifespan, work ethic and basically just about everything for this person.
To burn 1kg of body fat, you need to get a deficit of 7000kcal (actually 1kg of pure fat has 9000kcal but the body stores water and other tissue to support the stored fat, so if you lose 1kg pure fat, you would have lost more body weight). If by including sports one burns on average 2500kcal a day and consumes 2000kcal a day (500kcal average daily deficit), it would take abound 2 weeks for a kg of body fat. But this can be a consistent long-term reduction. Good guideline to achieve sustainable fat loss, without yo-yo effect, is staying on deficit of about 20-25% of caloric consumption.
This caloric deficit can be achieved by consuming less food (less calories in) and being more active (more calories out), preferably both at the same time. Eating healthy, calorie-sparse unprocessed foods makes it easier to manage appetite. Those foods are nutrient dense and fulfil your body needs unlike heavily processed thus named "junk" foods. And working out harder makes your body burn more energy and build/maintain muscle - the tissue you need to keep burning fat. Combination of high-effort activity and healthy higher-protein, low-sugar diet would make your body increase it's caloric expenditure, maybe such a huge person could burn 3000kcal a day, then the daily deficit could be 600-700kcal and lose 3kg a month instead of 2kg...
And actually swimming is much better than jogging for fat-burn - it burns more calories and allows to make more intense workouts (bursts or fast freestyle swimming) without straining joints or spine. The key to be taken is that any activity that helps burn substantial amounts of energy will do. But even if you work out a lot, it's very easy to out-eat the benefits of physical exercise. One hour of continuous swimming will burn 700-800kcal. One pizza is between 1000 and 2000kcal. Sport and diet (healthy, calorie-conscious) should be used together.
And this is why weight loss is result of long-term habits. It has taken years of caloric surplus to get to gain substantial amounts of weight, it can't take months to reverse the process. This is slow (yet, very rewarding) process. There is no quick-fix, there is no diet or pill that can do this without hard effort and determination. It requires huge amounts of long-term motivation to stay focused on your goal. The goal of losing around 80kg of body weight is achievable within about 2 years of hard work. In my experience coaching people, the motivation to change yourself usually comes from break-ups, ultimatums, sometimes as attempt to get out of long term depression, new-found health problems or other sources of personal epiphany. But I have never seen it work if the person doesn't really want it and is doing it for someone else.
Edit: One book that I read and really helped me was "Burn the Fat, Feed the Muscle" by Tom Venuto. I really liked it because it emphasised not on specific foods or routines but how to set goals, measure progress and change your mentality towards a consistent healthy lifestyle. It thought me that there are no shortcuts but that you could look the way you dream, not the way you believe it's possible. Hard work and consistency is the only way but once you change your mentality it gets much easier. It also explained macronutrients and how to make smarter food choices.
The simple answer is count calories and burn more calories than consumed while still getting enough other nutrients. However since discipline is the problem the answer will need to be more personal.
He needs to find his own motivating factor if not for himself then for his loved ones who want to see him live a long and healthy life.
The advice no. 1
Don't do any diet on yourself, always contact an expert (if the patient have any problem related to metabolism, diabetes or other it is likely a diabetologist will not suffice, and that the patient require support from other kind of specialists) be warned:
People doing diets on their self are just fu****g up their health because a wrong diet can be much worse than a non-correct alimentation (depends on how much trash someone eat of course). I want to specify that because all those forums/web stuff that cause anoressy are just fu****g the health of a lot of persons. This is the most important advice since everyone seems to be an expert at some kind of diet these days. Diets are harmful, only an expert should prepare a diet for you, and those expert are NOT You, your friend, your family member, your favourite blog. If an "expert" is just writing you blindly a diet on a piece of paper also take opinion from another expert.
The advice no. 2
Burn more energy, you should start gradually doing more exercise, if you do not enough exercise you will not burn any fat, if you do too much exercise you will ends up doing damage to your body (injuries etc.). Contact a doctor, but walking should be a good exercise, be sure to have a Hearth beat counter, when the weight of a patience is too much even walking too slow can be difficult so you don't want to ends up walking but doing the same exercise equivalent to a slim person running.
Swimming is a good exercise, as usual be sure to receive advice from an expert, if the exercise is to intense, you will just ends up burning sugar in blood instead of burning fat, and if you do exercise for too short time you will anyway not trigger fat burning of the body (fat is not the only energy store of our body in fact).
The advice no.3
Eat well, I'm not advising any diet, instead replace junk food with healthy food. Avoid sugar drinks, eat really slow (rule of thumbs, try to chew the same bite of food 30 times slowly), drink as less as possible during meals, and drink at least 1.5 liters in the whole day.
Good foods are foods without preservatives, fresh vegetables, fruit. Try to not overcook foods (list is not exaustive)
Bad foods are: fast foods (not only because of fat, also eating fast is bad), fried stuff, sugar, light or diet foods (list is not exaustive). Be warned, in our days sugar is everywhere, read carefully about ingredients of your food (sometimes even canned vegetables have sugar, added as preservative u_u O_o) and avoid it like hell (instead don't avoid good carbohydrates, wholemeal bread is really not that bad ;) )
By eating really slow you should become fully satisfied without eating tons of food. Eat as slow as you can and you will see that you are introducing less food in your body without getting hunger, this contributes to introducing tons of calories and other crap in your body. Also food should be a pleasure, so by eating it slow you are also taking some relax.
If you are tired of drinking only water try milk or sugarless tea (make the tea on your own). Avoid fruit juice (lot of sugar and anyway no vitamins), instead make your fruit milkshake (DON'T ADD SUGAR!)
Advice no° 4
Take less stress, stress damage body as much as smoke and alchol. Of course avoid alchol and smoke too, 2 bottles (50 cc) of beer OR 2 glasses of wine (1 glass = 20 cc) sohuld be your maximum in a week. What do you like? Bath? Music? WALKING? Do also what you like (unless is something that damages your health XD)
Advice no° 5
Contact an expert, setup a realistic weight loss plan ( 2 Kg/ month is not very much but should be doable) AND KEEP WITH IT. By following the advices above you should be able to lose much more than that without effort (keep in mind that a person with more weight will also burn more energy during exercise), if you don't lose weight then there can be plenty of troubles that needs attention from a specialist)
FINALLY
Take your time to experiment with food of course, you for sure don't want to ends up eating only food that you dislike, so it is your time to learn cooking you self new recipes (still avoid fried stuff), and especially experiment with fruits and vegetables (there are always vegetables that someone like and someone don't like, YOU WILL NEVER FIND WICH ONE if you don't take time to try em all).
LOVE YOUR LIFE, IF YOU DON'T LOVE IT CONTACT A PSYCHOTHERAPIST. Try to search for happiness (be warned, just please don't enter any cult or sect XD there are just too many people out there trying to brainwash other people).
It requires determination and some guts to lose such a large amount of weight, but it is definitely possible. I lost ~27kg in ~5-6 months (and another 20kg 2 years before that), so he could do it in ~1.5-2 years.
The most important thing is not exercise, specially at his weight, since even when doing some like water exercises (which include "acquagym" (and similar aerobic exercise in pools), swimming, etc), he is much more likely to get an injury. He needs to seriously reconsider his diet. At the moment, he needs to eat ~3k calories to maintain his weight. As such, he should reduce it to below that level. Since a kg of fat is roughly 7.7k, you can decide the calorie deficit based on how fast you want to lose weight. If he started eating like someone who's ~80kg (with his height and a sedentary lifestyle) should eat (~2100 calories/day), he would need just short of 2 years to lose all his weight (although that is a simplistic calculation, since his TDEE (Total Daily Energy Expenditure) will go down as he loses weight). He can try water jogging for a short period every day, since it'd speed up his weight loss, but it is not fundamental.
I'd recommend a diet focused on fats, while avoiding carbs, as fat makes you fuller for much longer. More meat, eggs, fish, and full-fat dairy, and less bread, pasta, etc. Have a look at keto for foods and recipes to try. I didn't follow keto to lose weight, but I gained inspiration from it. If he lacks determination he might benefit from a cheat meal per week, where he can eat whatever he wants.
Once he is down to ~100-110, he can start doing heavier exercise (light swimming, for example), and once he is even lower he'd benefit from going to the gym to lift weights (lifting is VERY useful to lose weight and fix your body (e.g. loose skin) after being fat). This would also benefit him due to his health issues (I have weak knees and a bad back, but lifting actually helped me to a degree (always remember to have proper form when lifting)), since things like squats can help build up strength in your legs and protect your knee, and deadlifts can strengthen your back, which will protect your spine. He should talk to a doctor beforehand though, obviously.
To make him stay committed, you will need to inspire him somehow. Once the results really start showing it is easier, but he needs to be fully motivated until then. You are the only person who knows what would motivate/inspire him, so I can't help much in that department.
TL;DR: It isn't hard, there are ways, but he needs commitment. There is no way around that.
This person is stubborn, but lacks determination you say.
The way forward has but one milestone then, change his motivation. A stubborn person can lose a tremendous amount of weight since stubbornness is an excellent trait to avoid losing motivation. Get him motivated, formulate a plan for diet mainly. Water jogging sounds like a great idea, but first and foremost trim the diet down to what is sustainable for a 80kg person.
Fast breathing exercises ( pranayama) I think will help for less mobile people. Ofcourse swimming is another best option, but one can do breathing exercises from ones own comfort, whenever they want with out any gadgets or special help.
Just adding to other answers, which contain some good technical information re. calories.
Short version: it's been very helpful to me, when feeling "not up to it", "not in the mood for it", or "too sore", to start with the exercise session regardless: once one start to warm up, the pulse rate goes up, and the sweat flows, all those feelings vanish like the morning fog, one feels so much better and alive afterwards, and really glad to have done the session.
Longer explanation: there are some endocrine-related factors related to low motivation (and perhaps depression?), which are maybe more difficult to quantify, but nevertheless important.
At a certain level of effort (which may differ from person to person and from exercise session to exercise session) endorphins come into play. I don't want to use the word "addictive" :-) but it is beneficial to start to enjoy exercise so much that it is done for its own sake.
In my opinion this can be improved on even further for people with an "indoors lifestyle" if the exercise can be done outside in fresh air and sunshine, preferably around lunchtime/noon - this improves Vitamin D levels, if done without sunscreen. (Ultraviolet radiation is needed for VitD production from cholesterol in the skin, a session of 20-40 minutes per day should suffice, but for longer exposures obviously the appropriate protective measures should be taken. The time limit nicely ties in with an adequate exercise session's duration.)
Exercise and sunlight also play a beneficial and not unimportant role in serotonin levels, again playing into the feeling of well-being. Also, tryptophan-rich foods may help to increase serotonin levels - tryptophan seems to be absorbed better if taken with some carbs. (In general I am in favor of low carb (LCHF, banting, atkins, keto....) diets, but it does seem that some carbs are needed in this respect.)
In my personal experience for an unfit person, one would need to increase distance/effort every now and then to keep up the challenge. My practical experience confirms the 2-year estimate, although improvements can already be seen after a few months or even weeks, every time that the previous distance is not challenging enough any more. These improvements are very gratifying and motivating, besides feeling more fit and well and being able to "do things" in general life much easier.
Some other points to consider:
A good sleep routine is also very important and beneficial in so many ways: stress relief, hormone normalization, well-being, energy levels, clarity of mind, muscle repair... The person should go to bed at the same time 7x365 (9 or 10pm latest) and sleep until rested (waking without an alarm). No "blue" lighting 1-2 hours before bed time.
A diet being propagated these days is derived from intermittent fasting, in that you only have 2 normal meals a day, late morning (say 9-10 am) and late afternoon (say 3-4pm). Without snacking. People on high-fat diets that keep one feeling satiated, may already have experienced something along those lines, just by eating only when hungry. In addition to decreasing calorie intake, those intermissions between eating help the digestive system to properly and completely digest all nutrients, while the inactive period is used for cleaning and self-repair, which optimizes digestive efficiency even further. The body gets all the necessary nutrients, "feels well-fed", and sends less craving (for carbs) signals. Modern carb foods are often much processed and refined, thus containing not many of the other needed nutrients.
It is helpful if exercise/eating/working/relaxation/sleeping can all be combined into an integrated lifestyle, then things tend to get done without much thought. Unfortunately the artificial or competitive nature of gyms and clubs may sometimes counteract this. I have taken up bicycling after "walking around the block" lost its challenge. (It is also easy on joints and spine, but can be done outdoors in colder weather.) To save time I combine my ride with other necessary chores like a trip to buy groceries (smaller amounts of fresh vegetables 2-3 times a week to help with a more healthy diet) or the library, or even to work (as many are able to do). A downside can be the dangers and exhaust fumes of traffic, if no dedicated paths are available.
A good diet. Some swimming but not swimming just be helped in water . And massage. But most important a good diet and some small exercise
