09-04-2018 03:56 - edited 09-04-2018 06:53
09-04-2018 03:56 - edited 09-04-2018 06:53
We are often asking ourselves what caloric deficit we should use to lose weight in a sustainable manner, but usually think in absolute terms: for instance, should it be 500 or 1000 calories? One way to make it more relative is to aim at losing a certain amount of weight as a percentage of bodyweight: for instance, 1% of bodyweight per week, 10% of starting weight over three months. However, this still doesn’t fully take into account what I would call the "relative intensity" of the diet. I’ll try to explain what I mean using two hypothetical subjects, A and B.
A is a 60-year-old woman, 5’ 2 tall, 164 lbs, sedentary.
B is a 30-year old man, 6’ tall, 221 lbs, highly active.
Both have a BMI of 30.0, so are presumably carrying quite a bit of extra weight for their own good.
Person A has a BMR of 1267 calories and a TDEE of 1521 calories.
Person B has a BMR of 2000 calories and a TDEE of 3451 calories.
For the sake of simplicity, I’m using the standard equation found in this online calculator, which obviously doesn’t take into account any individual differences (possible medical conditions etc.).
Let’s assume both go for the standard 500 calories daily deficit, which is supposed to result in a weight loss of 1 pound per week. Person A would be eating 1021 calories, which is 246 calories below her BMR and 67% of what her body would normally need at maintenance. Person B would be eating 2951 calories, which is 951 above his BMR and 86% of his maintenance level. Clearly, that same absolute deficit would be much harder to sustain for A than for B. Person B could very well go for a 1000 calories deficit and still be better off: he would still be eating 451 calories above his BMR and 71% of his maintenance calories.
Of course, B would need to lose 37 pounds to bring his BMI down to 25.0, while A would "only" need to lose 27.5 pounds.
In that example, we saw there are several variables that affect the relative intensity of a diet: gender, age, size (height / weight) and activity. Of these, weight and activity are the only ones we can have an impact on, and weight is what we are trying to change, so this leaves us with activity as the only true adjusting variable.
I’ve tried to put this into practice in my own dieting efforts: since I can’t change the fact I’m 57-yo and 174 cm tall (which results in a relatively low BMR), I’ve strived to significantly up my activity level from my usual baseline while actively dieting down to a lower weight. During my last weightloss phase, I estimated I ate 1178 calories above my BMR, for a relative intensity of 83% of my maintenance level. I was able to lose about 6 kg in 12 weeks (starting from a relatively lean level), without feeling extremely hungry at any time, nor completely depleted towards the end.
So while weightloss success is primarily about eating, activity can be a significant contributor too.
Dominique | Finland
Ionic, Aria, Flyer, TrendWeight | Windows 7, OS X 10.13.5 | Motorola Moto G6 (Android 9), iPad Air (iOS 12.4.4)
Take a look at the Fitbit help site for further assistance and information.
09-05-2018 08:38
09-05-2018 08:38
@Dominique -- your hypothetical example nicely illustrates one of the reasons why, when a lot of couples "go on a diet together," the larger person (usually the man in male/female couples) seems to lose weight more more "easily." The daily burn is just higher for bigger people even if the BMI is the same.
Adding movement helps a lot in getting to the point of be able to lose weight without going to extremely low levels of calorie consumption.
Scott | Baltimore MD
Charge 6; Inspire 3; Luxe; iPhone 13 Pro
09-27-2018 11:03
09-27-2018 11:03
@Dominique your example definitely confirms what I have personally experienced. I increased my activity by quite a bit, and even though I am more hungry, I actually get to eat!!! I eat quite a bit and this helps me not feel deprived and keeps me fueled to stay active. I could not imagine trying to lose weight by diet alone...I don't think I could be successful at it. I would have to eat such small amounts of food to shed the weight and I would be very cranky and miserable or Hangry :). And eating so few calories would make it very difficult to carry on the duties of my very busy life, full time job as a teacher, and a business I have to run on evenings and weekends. I need to EAT!! to remain sane and healthy! 😉
Thanks for this great example 🙂
09-30-2018 14:55
09-30-2018 14:55
@Dominique the interesting thing about exercising is that it plays lot more important role during weight loss and maintenance than just burning a few extra calories. Trying to answer a question of why I am always hungry I found out that probably I'm leptin resistant ( sometimes called "brain starvation" ) which is something I had to build when I was obese. It's really hard to retrain the brain even after such a long time. Even if my body is about to explode, my brain still tells me to eat. It's very frustrating. Adding more exercise, however, helps me with managing this situation. One, it makes me burn more calories daily but also, what is a lot more important to me, it suppresses hunger. Exercising makes me consume less food because my brain is not craving for it. It helps during weight loss and is still a big help when you try to keep the weight off. That's why I have my small theory that active people stay fit not because they are active but because they consume less food. It's easy to eat more than one burned during exercising but if the brain is not demanding to be fed it's much easier to control the situation.
10-05-2018 17:46
10-05-2018 17:46
Good post. This is something I am addressing at the moment.
I'm 46, 5'9 and weigh 155lbs with 19% bodyfat - which is a healthy weight for my frame. When i got my Fitbit Blaze I weighed 186 lbs with 27% bodyfat. I never really thought about BMR TDEE and wasn't too clued up on it when I got the Blaze, I simply made a plan and went on a 500 cal deficit and did 1000 steps a day. That and diet change saw the excess weight literally fall off in hardly any time at all. I'd hardly put in any effort that it felt like cheating or something.
Anyway, what seems to me to be a lot more tough, is when you're at a healthy weight but you now want to get an athletic physique. And why not? If you get so far, it makes sense that you'd want to continue to make new goals to keep you motivated. The issue is though with me at least, is any sort of deficit in my calories now could potentially see me eating below my BMR - which is about 1600 cals a day. If I entered a -250 cals a day deficit on fitbit plan, without activity, it would have me eat about 1350. I'm eating on average 1700 to 1900 a day and sometimes wonder if that is a little too low but I feel fine, weight is stable and bodyfat is very, very gradually coming down. It's at this point that I'm aware that any further physical changes I wish to make are going to have to be 'earned' by increasing physical output, increasing things like resistance training, cardio. The issue I have however is whether I maintain my current level of eating or increase it but what I don't want to do is increase my food intake whilst increasing my activity and be exactly on a balance - which is pretty much where I am now. The other issue is, without increasing food intake, I'm not giving myself enough enery for the actual added demand.
It's a head scratching thing for me at the moment so if anyoe can chime in with some suggestions, I'm all ears. 🙂
10-06-2018 07:22 - edited 10-06-2018 08:48
10-06-2018 07:22 - edited 10-06-2018 08:48
The comparison between a 60 year old woman and a 30 year old man is not really fair. First of all, women tend to store "MORE" body fat compared to a man, so using BMI is completely moot. The American Journal of Nutrition published a study that illustrates below..
10-07-2018 03:13
10-07-2018 03:13
@MVibe wrote:Anyway, what seems to me to be a lot more tough, is when you're at a healthy weight but you now want to get an athletic physique. And why not? If you get so far, it makes sense that you'd want to continue to make new goals to keep you motivated.
Sure, that’s exactly how I see things: it’s not a finite process with a beginning and an end, it’s open-ended/never-ending!
It's at this point that I'm aware that any further physical changes I wish to make are going to have to be 'earned' by increasing physical output, increasing things like resistance training, cardio. The issue I have however is whether I maintain my current level of eating or increase it but what I don't want to do is increase my food intake whilst increasing my activity and be exactly on a balance - which is pretty much where I am now.
Changing body composition involves losing fat and gaining muscle. While it may be possible to do both if/when you are significantly overweight, it’s very hard once you are at a normal/healthy weight, which appears to be the case for you. The optimal way to do it (so I’ve been led to believe) is to do things sequentially, alternating between fat loss phases (when you are eating at a deficit) and muscle gaining phases (when you are in a caloric surplus), possibly interspersed with maintenance phases (to let your body get accustomed to the new lower fat level, or the newly gained lean mass).
Cardio training is particularly useful when losing fat, as it will allow you to eat enough food while still being in a deficit. It obviously also has benefits from a general health and fitness perspective. Resistance training is what it takes to gain muscle (while in a caloric surplus), and to preserve lean mass (while in a caloric deficit). Diet-wise: eat enough protein (to built muscle/preserve lean mass), enough carbs (to fuel your resistance training workouts), get the rest of your calories from healthy fats (needed for hormonal balance); generally speaking: get most of your food from whole/minimally-processed sources, eat your veggies & fruits (micronutrients and fiber).
I’ve been experimenting with this for the past couple of years. The latest fat loss phase (early June to early September, 12 weeks) went well, with BF% going from 17.5 to about 13.5%:
I had planned to have an 8 weeks maintenance phase after it (currently on week 6/8), but I’m pondering whether I should make it longer. This is because BF% has continued to decrease, albeit very slowly, even though I’m no longer in a deficit.
The challenge for me is gaining weight slowly enough, so as to minimize fat gains. My next attempt will be to gain at no more than 0.2-0.3 kg per week in average, and hopefully end up with a BF% lower than 17+, where I was last June.
Dominique | Finland
Ionic, Aria, Flyer, TrendWeight | Windows 7, OS X 10.13.5 | Motorola Moto G6 (Android 9), iPad Air (iOS 12.4.4)
Take a look at the Fitbit help site for further assistance and information.