Over the last six weeks, I’ve become mortal enemies with this 15 LB weighted vest:
But really, I wore this vest every day through the latter half of my diet because science shows us it could help prevent metabolism from slowing, keep hunger lower, and allow you to lose fat on more calories.
A few people have been asking if it really helped… could it be a game-changer for their fat loss?
Well, I just finished my diet, so the final results of the weight vest experiment are in.. and to be honest, I was surprised by them.
In today’s blog, I’ll break down the exact process I used throughout the weight vest experiment, the results, and how (or if) it should be applied for anyone else in a fat loss phase.
So to understand why I undertook this, you first need to understand the potential benefits of wearing weighted apparel like this during a fat loss phase.
BENEFIT #1: INCREASE CALORIES BURNED VIA NON-EXERCISE ACTIVITY
A large part of your metabolism slowing down or speeding up as you lose or gain weight (respectively) is the fact that it takes fewer calories to move a smaller body through space and keep it alive at rest, and more calories to move a larger body through space and keep it alive at rest.
A 180 pound version of yourself walking 8k steps per day and training 4x/week will burn more calories both while moving and at rest than a 150 pound version of yourself doing the same amount of activity.
So your metabolism is in a large part a product of your current body size.
A bigger version of your body burns more calories, and thus has a faster metabolism.
The problem here is, the goal of dieting is literally to make your body smaller.
As your body gets smaller, it burns fewer calories/your metabolism slows. So food often must be decreased a few times over a diet to continue to lose fat at the target rate…
…unless you were able to replace the weight loss via fat with weight added by a weight vest.
This is the most clear benefit of the weighted vest (as long as you’re wearing it consistently) – by replacing body weight lost with weight added via a weighted vest, we can decrease the amount metabolism slows – while you’re losing fat, your body doesn’t “weigh less”, so calories burned stay high.
BENEFIT #2: POTENTIAL DECREASE IN HUNGER & METABOLIC ADAPTATION DUE TO ENERGY FLUX
Fat loss basically comes down to energy.
Energy (calories) in < Energy (calories) out = fat loss
Now the energy out side of the equation basically determines whether we can eat a lot or a little while dieting.
→ People that don’t get much daily movement of course have to eat less to keep energy in < energy out.
This move less, eat less approach to fat loss is known as low energy flux.
→ People that get a lot of daily movement can eat more and still lose fat.
This eat more, move more approach to fat loss is known as high energy flux.
To quote James Krieger when describing why energy flux matters:
“There is evidence that your body’s ability to naturally regulate its body weight is most effective in states of high energy flux, rather than low energy flux. High energy flux may protect against some of the metabolic adaptation that occurs with weight loss, and may reduce sensations of hunger. For example, endurance athletes who establish an energy deficit through exercise while maintaining a higher calorie intake have a higher resting metabolic rate compared to untrained subjects in a low energy flux condition. Older adults have a lower resting metabolic rate and lower muscle sympathetic nervous system activity when in a low energy flux state compared to high energy flux state. Following weight loss, obese subjects had a higher resting metabolic rate and reported less hunger and more fullness in a high energy flux condition versus low energy flux condition, despite both conditions being in energy balance. Low energy flux also predicts future increases in body fat.
This data suggests it is better to establish a deficit with a higher energy expenditure and higher calorie intake, rather than lower energy expenditure and lower calorie intake.” (1)
The added weight of the weight vest increases the calorie cost of the movement you’re already doing, pushing you towards high energy flux.
BENEFIT #3: GRAVITOSTAT
Again, pulling heavily from what I’ve learned from James Krieger’s excellent article on this topic.
Until recently, it was thought that your body weight / body fat was mostly regulated by the hormone leptin.
For most of us, when our body fat dips below our body’s comfortable norm, leptin levels decrease, hunger increases, which tends to cause us to eat more and regain the weight.
However, some recent rodent studies seem to indicate there could be another mechanism to regulate body fat unassociated with leptin. This mechanism has been dubbed gravitostat.
In this study, scientists implanted rodents in the bellies of overweight rats. Shortly after the implantation, the rodents suddenly lost a considerable amount of weight.
Interestingly, these rodents seemed to lose until their body weight including the implanted weight was the same as their non-implanted overweight counterparts in the control group.
So basically, adding the weight in their bellies seemed to trigger their bodies to drop weight quickly, and return their body weight to it’s previous comfortable norm.
This fat loss was not caused by an increase in calories burned. Instead, the rodents simply saw a decrease in appetite after being implanted.
But, when the weighted implants were removed, the rats gained back the weight.
So the theory behind all of this…
Osteocytes are bone cells that sense loading on bone to stimulate increases in bone density. An increase or decrease in osteocyte loading sends a signal to the brain to decrease or increase hunger.
By this theory, adding weight via a weighted vest would increase osteocyte loading and decrease the amount of hunger experienced on a diet.
To sum up, rodent studies indicate your bones may help regulate body weight/fat by sensing load. Increased load could = decreased hunger signal.
BENEFIT #4: IT’S BEEN PROVEN EFFECTIVE BEFORE
James Krieger actually documented one of his clients prepping for a bodybuilding show while replacing weight loss via weighted apparel (check out his write up on the process here).
This client went from 165 lbs to 145 lbs in 15 weeks.
Normally, he would have had to drop down to 1400-1500 cals to reach 145. But instead, with the addition of the weighted apparel he was able to…
→ Keep calories at 2300/day the entire prep
→ Keep steps at 9500 per day and never had to increase cardio
The bodybuilder, Eric, was able to get stage lean on significantly more calories and less cardio than ever before, and noted that it was the easiest bodybuilding show prep he’d ever done.
Unfortunately, I didn’t think to start wearing the vest until I was seven weeks into my thirteen week diet.
But, once I decided to take it on, here are the guidelines my coach and I created:
1. The vest must be worn for 6 hours daily
2. The entirety of these 6 hours, you must be standing or walking – this meant that while I was working in the vest, I’d use my standing desk. We hypothesized standing was necessary to reap the benefits of gravitostat.
3. ½ my daily 10,000 steps must be accomplished wearing the weighted vest – For me, this usually meant that I would put the vest on first thing in the morning. I’d take it off ~ 1-2 hours later to train, and then wear it again at my standing desk until my back/hips got tired (this usually meant wearing it in ~1-2 hour chunks), when I’d take it off and sit for a bit (again, usually 1-2 hours).
I’d repeat this process until I hit the “six hours worn” mark. I really tried to be done with my six hours by the time my girlfriend got home from work, as she didn’t seem to be as entertained by this whole process as I was.
As mentioned, I only wore this vest in accordance with the above guidelines the final 6 weeks.
I didn’t realize what a large undertaking this would be when I initially committed to it. My feet, hips and lower back were wrecked for the first week of wearing the vest – this first week seemed to be the “adaptation period”.
After this, my body got much more used to the vest, and it was much more manageable.
I also failed to think through the fact that I would also be wearing this vest for 6 hours on the weekends… which was quite a bit different than just wearing it during my weekday at my home office.
Fortunately, we didn’t travel too much during this timeframe, and I was still able to make it work on the weekends (albeit, with a lot of weird looks from others).
So to get into the results…
After spending a year focusing on eating more food and building muscle and intentionally gaining weight, it was time to cut off the fluff I’d added.
Hence, my 13 week diet started.
Over the course of my 13 week fat loss phase (3/28 – 6/29), I went from 232.4 to 203.9 (for a total of 28.5 pounds lost).
I wore the weighted vest the final six weeks. During this time, I went from 215.2 to 203.9 (11.3 lbs lost).
AVERAGE RATE OF LOSS PER WEEK:
→ First seven weeks (no weight vest): 2.46 lbs per week
→ Last six weeks (wearing weight vest): 1.88 lbs lost per week
With this breakdown, it looks like the rate of loss slowed just a bit when adding the weighted vest… but really, I was surprised with how high the rate of loss stayed, considering:
1. Steps stayed very similar throughout this process – The final three weeks of the diet, we bumped my step goal to 10k per day (I was averaging 9k before this). So a slight increase, but not a large jump by any means.
2. We only decreased macros once (before I started wearing the weighted vest), and just by 25g of carbs – to start Week 5 of the diet, we decreased calories from 2100-2200 to 2000-2100.
Admittedly, this is a pretty aggressive diet for a 200 lb+ dieter. But as you learned earlier, as your body gets smaller, you burn fewer calories and metabolism slows.
For losing 28.5 lbs, the rate of fat loss barely decreased.
You also have to consider that my body was getting smaller, so the percentage of total body weight lost stayed very similar across the diet:
→ At 230 lbs, losing 2.3 lbs per week = losing 1% of my body weight per week
→ At 200 lbs, losing 2 lbs per week = losing 1% of my body weight per week
Percentage of total body weight lost is what we adjust our online clients nutrition based on, and is a much better way to determine how well a fat loss phase is going than total weight loss (losing 1.5 lbs per week would be a large amount for a 110 lb individual, but a small amount for a 250 lb individual).
Relative to diets I’ve done in the past, I was pleasantly surprised at how consistent my rate of loss stayed while keeping macros and cardio very similar through the entire diet.
I really didn’t notice a difference in hunger from previous diets (although this is very hard to measure). As a whole, if there’s one benefit I’m more skeptical of with the weight vest, it’s gravitostat.
So the real question here…
Should you wear a weighted vest during your next diet?
→ The weighted vest did seem to yield a much more consistent rate of loss (with minimal adjustments to macros and movement) than I’d seen before.
→ That said, it is also really a pain in the ass to wear for 6+ hours every day, for weeks on end.
If you don’t work from home, it’s likely frowned upon to wear an armored vest to the office, and many people simply won’t want to be the person explaining why they’re wearing a weighted vest at every social event on the weekends.
A client that didn’t want the hassle of wearing a weighted vest could achieve the same by simply adding in a few more cardio sessions per week, dropping calories a small amount more, or bumping steps by 2k per day – and really, I think most people would prefer these over wearing the weighted vest constantly.
But, using it as more of a supplement (i.e. worn 2-3 hours per day in the morning and/or evening, and on all of your walks/as many of your daily steps as possible) could be a much more realistic option for most of our clients, and would likely yield most of the benefits from above.
In summary, if you view it as a supplement to your weight loss (and realize that it won’t make a massive difference in your progress), replacing body weight lost with a weight vest while dieting can help you make a bit faster progress.
If you feel that wearing a weight vest consistently would significantly hamper your lifestyle… or just annoy the hell out of you, it’s likely not worth wearing.
If you’re sick of spinning your wheels in the gym and making these same mistakes over and over, click here now to apply for Online Coaching with our team.
You’ll get fully customized training + nutrition protocols fit to your specific goals & lifestyle, and expert guidance and accountability through every step of the process.
Jeremiah Bair is a certified nutrition coach, strength coach, and owner of the online coaching business Bairfit. Check out his Podcast and Instagram for more educational content.