> During fasting days, participants fasting for one day/week were allowed to consume 400 Kcal/day, while participants fasting for two consecutive days were allowed 500 Kcal/day. During non-fasting days the dietary regimen provided 1350 and 1700 kcals/day for women and men, respectively, and a macronutrient distribution consisting of 35% protein, 35% carbohydrate, and 30% fat.
That's somehow more calories/day than I would expect for a "fasting day", and fairly restrictive over-all. I'd be curious to hear how these compare to someone on the 1350/1700 kcal/day diet 7 days a week.
> Extending beyond 4-weeks reduces compliance and may be overly excessive for a caloric restriction and 2 day IF and create undue metabolic, physiologic, hormonal, and psychological stress in the study participants.
Also something I was wondering, the repeated emphasis on short-term benefits has me wonder how the participants did after the trial. Does it do much good if you drop more but it bounces back?
> Isagenix International, LLC (Gilbert, AZ, USA) provided all meal replacement shakes, bars, beverages, and supplements.
> Whole Blend IsaLean® Shakes, Cleanse for Life®, Ionix® Supreme, Collagen Bone Broth, AMPED™ Hydrate, Harvest/Whey Thins™, IsaDelight® Chocolates,
> This study was supported by a grant (IRB#: 1911–859) from Isagenix International, LLC
> P.J.A. (the primary author) is a member of the scientific advisory board at Isagenix International LLC, the study’s sponsor. E.G. and A.E.M. are employed by Isagenix International LLC.
Ok, that reads as very suspect, now.
For men, they are running a 300 kcal deficit for 5 days and 1500 kcal deficit for the other two. For a total of 4500 kcal per week. Or losing about a pound and a half.
Now, seeing as this is for overweight people, it's likely to be even more. As it takes more calories per day to maintain higher weights. So if the person's maintenance is about 3000 kcal/day, that's going to be a deficit of roughly 11,500 kcal per week. Which is close to 4 pounds.
But then again, restricting yourself to just 2000 kcal/day would have you lose about a pound and a half per week.
Because, when you are very overweight, lots of things work.
This right here is the first and most important reason to be skeptical of any study on weight loss. None of these things ever turn out to do anything useful on a time horizon that matters.
If you want to know how to lose weight for a few weeks you don't need a peer reviewed journal, just go get a "women's health" magazine and read about several ways that really do probably work to lose weight in that timespan.
And then you gain it back.
Given a person undergoes an intervention, succeeds in losing 40 pounds, then gains it all back over the next five years, that sounds like failure in a vacuum, but that means they spent five years not gaining more weight. If the non-intervention counterfactual is they would have ended up 40 pounds even heavier, then intervention is still a win. Yo-yo dieting with lifetime net zero progress is still better than steadily getting fatter for the rest of your life.
It's (always) worth skimming the article, or at least the headline. From the subheadline:
> *Given the same energy intake and expenditure*, intermittent fasting two days versus one day per week increases weight loss in overweight men and women
This study isn't saying "2 day IF is a miracle weight-loss cure and you should just do it bada bing bada boom weight loss solved". It's holding everything constant except the number of fasting days, and finding that it's (quite dramatically) more effective in the short-term.
This is a data point, not a weight-loss plan. It doesn't call for "skepticism", just careful reading and limited application (or for a start, reading the article/headline at all).
Nutrition is intensely complicated and devilishly difficult to study. But for scientifically-literate people who take it seriously, data points like this shed light on limited portions of the "solution space". This is crucial to mapping out the space enough to understand how to improve your own diet; it's not amenable to an impatient approach that expects every study to be a magic bullet.
Even ignoring the signal that this provides, the absolute minimum value of this study is that somebody who's already doing a time-limited IF-1 diet can switch to a time-limited IF-2 diet. That's valuable in and of itself.
> If you want to know how to lose weight for a few weeks you don't need a peer reviewed journal, just go get a "women's health" magazine and read about several ways that really do probably work to lose weight in that timespan.
With the same improvement in hunger levels, hormone profile, and cardiometabolic health (all mentioned in the for both the control and treatment)? I highly doubt it. Even assuming that IF isn't sustainable[1], people do have short-term weight loss goals sometimes, and IF provides a path to do so that keeps metabolic and hormonal health in mind relative to traditional crash dieting.
[1] I've been doing it for....five years now? Not only did I lose a reasonable amount of weight early on, it's been helpful for maintaining during a life phase of suddenly-expanding waistlines among my peers. Plus it's trivial to dial it up slightly when I do feel the need to tighten up a little.
I found IF gave me a tool to help me control my appetite for the rest of my life.
Self control is best method for maintaining weight, as it's free and guaranteed to work if used.
When you eat in a calorie surplus, your glycogen stores are full. When you eat in a sustained deficit, you operate with very low glycogen stores.
This is why when you start a diet you often immediately lose 5 pounds in the first few days.
This is also why when you are dieting and have a huge cheat meal, you "gain 5 pounds" and then lose it again immediately upon resuming your diet. It's mostly retained water since your body converts the giant influx of calories into glycogen then burns it off over the next several days.
If you want an easy version, look up fast mimicking diet by Dr. Longo. Prolon sells premade kits.
In my experience, the first day is by far the most difficult. I find that it's most effective to start fasting on days where I am going to be occupied with something, since I don't think about food when I'm active.
I'd be miserable if I attempted to fast on a day where I was lounging around watching TV.
I did Paleo in 2012 for several months with success. However, I have tried Keto/low carb again several times with less success. Specifically with Sated meal replacement. I get muscle cramps and other side effects that I assume are due to changes in the diet.
> During fasting days, participants fasting for one day/week were allowed to consume 400 Kcal/day, while participants fasting for two consecutive days were allowed 500 Kcal/day. During non-fasting days the dietary regimen provided 1350 and 1700 kcals/day for women and men, respectively
That seems like the first claim is just untrue and the 2-day-fasters are consuming fewer calories overall? If all the non-fasting days are the same for both groups like this says, then the 2-day-fasting men are consuming 1100 fewer calories per week (and 750 fewer for women). Even if intermittent fasting did nothing at all, I would expect that extra calorie deficit to result in more weight loss.
I think that the logic of giving even less to those fasting is pretty obvious that it would lead to more weight loss.
You can read the full study here, but it seems to confirm a caloric defecit on the IF2 and IF group vs control.
https://nutritionj.biomedcentral.com/track/pdf/10.1186/s1293...
...
IF1-P, 9058±692 kcals/week vs.
IF2-P, 8389±438 kcals/week
A proper methodology would be to have all 3 groups consume the same 7-day baseline diet for 2 weeks, then switch into the IF groups and monitor increases in rate-of-change for body weight vs net body weight difference before/after. There should also be similar caloric input for all groups before and after program to see if there is actually an additional benefit to intermittent fasting vs caloric input reduction.
To have a caloric restriction below 2000 per day is a restricted diet to me - not that that's bad.
I'm literally twice the size of my friend, at the same BMI (more than a foot taller). So should I be eating 3400? Or should they be eating 850?
You're supposed to:
- count your calories and maintain the same calorie intake for a while
- measure your body weight or other metric you want to change throughout
So, if you're eating 2,500 calories a day and see you're gaining weight, you have a baseline you want to go below to lose weight.
The interesting fact however is that typically, these mechanisms are not fully activated until at least 24 hours of fasting.
Well, this sounds to me like they know it has an effect but they don't actually know the full story on why it works.
"We know it works because after 24 hours, X happens" does not explain why it works when you aren't hitting that mark. Sorry.
This study tells us very little. Small sample size, constrained diets without a proper control (protein pacing without IF, or no restriction at all), short evaluation horizon.
There could be something to it, but as they say, that requires a lot of further study. In itself this study provides a hint, certainly nothing close to an authoratative conclusion.
N=10 in each group, and the IF-2 day group has a single clear outlier (someone who is obviously larger than everyone else).
If so, it might be a good idea to go and check your blood sugar.
No, I really don't want to start a discussion on this - I just find it funny that most of them seem to imply fasting as 0.0 calories per day, without explicitly mentioning it. And then the discussion about the coffee follows...
Weight loss slowed down naturally once I've reached a healthy weight range.
That's a lot of protein, comparable to the amount that bodybuilders consume. Does fasting increase protein requirements?
"Low Carb" for 2200 Cals a day : Carbs:138g Protein:248g Fat:73g
Via: https://musclewiki.com/Macro_calculator
I think most of the modern world is actually not getting enough protein.
Every single person I talk to when I help coach them on macros we find out they are not getting near enough protein. (Myself Included)
[1] https://healthyeating.sfgate.com/taking-200-grams-protein-sa...
He convinced me that I needed more protein than ever before. This guys was massive, and had success locally at competitions. So I took his advice and started to consume on average 350 grams of protein, he wanted 400 but I just couldn't do it.
I'm honestly not sure if it made a difference but I was at my most biggest, and strongest when I trained with him.
There's new discussion these days that western diets are woefully under consuming protein. Based on my own anecdotal evidence this year, I would certainly agree.
I've always wondered - do the 0.8 / 1.6 grams of protein per kg apply equally across someone's whole weight? If someone has a lot of body fat compared to lean mass (bones / muscle etc), would the protein requirement per kg go down accordingly?
In other words, does having more fat tissue increase protein requirements, or should we instead think of protein requirements only for lean body mass?
For reference a 27.5 BMI is 5’9” at 186lbs. I can attest that when I’m well muscled, nobody thinks I’m fat at 186, but when I’m not yolked, I look like a tad doughy.
The average adult male in the US has a BMI of 26.6 btw…
My understanding is no, the body conserves protein during fasting conditions.
> a group of 20 participants
That is unscientific and the results are anecdotal at best.
I'll just be fat.
I'm having a lot more success with a changed way of life, but to do that I also needed the support of those around me. In particular I needed to get my wife on board to help me make better food choices and to have healthy choices at dinner time. She has been incredible and very supportive. Once that shifted into place all the pieces came together. What's interesting is that I almost needed all of them in place to really start seeing the changes I wanted.
What worked for me:
I try and walk at least 30 mins everyday.
I track my activity using an apple watch.
I track what I eat since I don't really know the macronutrients in foods or the calories (lose it app, paid subscription). Before I would just eat until I felt full. What's really interesting is that eating more of the right things I feel just as full but it's many fewer calories and a much better macronutrient breakdown.
I try and get a lot more protein in my diet.
I try and drink at least 3L of water, I think this helps me to not feel hungry as well.
I've been at this for just about 2 months now and I feel and look much better than I have in a long time. I really think that these changes are ones that I can stick with for the rest of my life.
(It looks like shouty 'if' at the moment, and then 1/2 days/week what?)
Submitted title was "IF 2 days vs. 1 day/week increases weight loss in overweight m/f" but I think we can just use a prefix of the article title. I've changed it to that now.
