Varying calorie intake

Status
Not open for further replies.

Bioexplorer

GLP-1 Apprentice
Chief Expert
Member Since
Apr 19, 2026
Posts
48
Likes Received
205
Location
Lexington, KY
Is anyone still incorporating a fasting day after starting Reta? Is there any evidence that fasting 24 or 36 hours per week followed by normal intake on the other days reduces muscle loss? So all weight loss occurs on one or two days and you maintain no calorie deficit for the remainder of the week.

I'm a believer in intermittent fasting. Reta makes it MUCH easier. Do the benefits translate? Amazingly, it would probably take some effort to consume enough calories on the no-fasting days.
 
if you are in a steep caloric deficit you will lose both fat and muscle, there is no way around that. but the best way to maintain current lean mass(that is more than just muscle btw) is to do some sort of strength training. that will shift the ratio to more fat loss vs lean mass but you will still lose lean mass, there is almost no way around it, but you can make it so the majority you lose is bodyfat.

i have seen many discussions about bulking on reta, utilizing the better nutrient partitioning with good results, might be something to look into since you are already kinda thinking along the lines of a daily unguilting calorie intake/ carb cycling diet.

imma mark this thread because im interested to see what someone with alot more experience than me has to say on the subject.
 
There is a shitton of terrible reporting on this topic so it's really hard to get to the bottom of this. But if you dig into the studies a lot of them seem to show that fasting might be better for preserving muscle than regular dieting.

quoted said:
On the other hand, preservation of fat‐free mass, at the cost of fat mass during weight reduction is unexpected with the level of energy restriction that ADF [alternate day fasting] prescribes. To our knowledge, this is the first review to report this finding. The mechanism for this effect, if confirmed by other studies, is unclear, although it is possible that either the fasting period is brief enough that there is less loss of lean tissue in the first place, or that the days where full energy needs are met allow for recovery of fat‐free mass by rebuilding lean tissue lost on the fasting days.

Alternate‐day versus daily energy restriction diets: which is more effective for weight loss? A systematic review and meta‐analysis - PMC

Alternate‐day‐fasting (ADF) has been proposed as an effective dieting method. Studies have found that it also can increase life span in rodents, and reduce inflammation in humans. The aim of this paper was to systematically review the efficacy of ...

pmc.ncbi.nlm.nih.gov

quoted said:
In contrast, less fat free mass was lost in response to intermittent CR [calorie restriction] versus daily CR. These findings suggest that these diets are equally as effective in decreasing body weight and fat mass, although intermittent CR may be more effective for the retention of lean mass.

Intermittent versus daily calorie restriction: which diet regimen is more effective for weight loss? - PubMed

Dietary restriction is an effective strategy for weight loss in obese individuals. The most common form of dietary restriction implemented is daily calorie restriction (CR), which involves reducing energy by 15-60% of usual caloric intake every day. Another form of dietary restriction employed...

pubmed.ncbi.nlm.nih.gov

quoted said:
Long‐term fasting did not alter muscle metabolism or performance, nor induced structural or inflammatory changes. The decrease in muscle volume is minor when accounting for glycogen and water depletion during fasting. Fat is relocated to the intracellular compartment of myocytes. Both anaerobic and aerobic metabolic pathways remain unchanged after 12 days of fasting in both sexes and older subjects. This suggests that human muscles, like those in animals, have evolved to withstand seasonal food shortages and endure long fasting periods.

Impact of Long‐Term Fasting on Skeletal Muscle: Structure, Energy Metabolism and Function Using 31P/1H MRS and MRI - PMC

Fasting shows promise for public health, but concerns about muscle loss hinder its acceptance, particularly among the elderly. We explored the impact of long‐term fasting (12 days, 250 kcal/day) on muscle structure, metabolism and performance. We ...

pmc.ncbi.nlm.nih.gov

Some other studies show no difference

quoted said:
Both the time-restricted–eating and daily-calorie-restriction diets led to loss of lean mass, abdominal visceral fat, subcutaneous fat, and liver fat; there were no differences between the groups.

https://www.nejm.org/doi/full/10.1056/NEJMoa2114833

So results unclear lol. But in any case Bbbilly's right that using your muscles during the fast is the best way to preserve it during weight loss, as well as adequate protein intake.
 
deleted.user.16 said:
So results unclear lol. But in any case Bbbilly's right that using your muscles during the fast is the best way to preserve it during weight loss, as well as adequate protein intake.
Thanks for those references. I've only been on low dose Reta for two weeks now but am losing weight faster than desired. Despite lifting hard 3 days a week, I suspect that I'm losing some muscle.

Before Reta, I was making steady gains in weight or reps since resuming training after a 3 month break due to injury. But no gains in the last two weeks and the sets have actually gotten more difficult with need for longer breaks. I know I need to be more diligent with protein intake and type. I'm still learning.

Just ordered some whey protein powder and taurine since I've read that is a key amino acid for muscle recovery. Any other suggestions are welcome. I can't afford muscle loss since I'm still trying to overcome atrophy and recover from injury.
 
Bioexplorer said:
Thanks for those references. I've only been on low dose Reta for two weeks now but am losing weight faster than desired. Despite lifting hard 3 days a week, I suspect that I'm losing some muscle.

Before Reta, I was making steady gains in weight or reps since resuming training after a 3 month break due to injury. But no gains in the last two weeks and the sets have actually gotten more difficult with need for longer breaks. I know I need to be more diligent with protein intake and type. I'm still learning.

Just ordered some whey protein powder and taurine since I've read that is a key amino acid for muscle recovery. Any other suggestions are welcome. I can't afford muscle loss since I'm still trying to overcome atrophy and recover from injury.
I get where you’re coming from. What you’re describing is actually pretry common when starting Reta, especially if they were training consistently before.

At just two weeks in, it’s probably not true muscle loss yet. It’s more likely a mix of lower calories, lower carbs, and less glycogen in the muscles. That alone can make workouts feel way harder, even if you haven’t actually lost meaningful muscle tissue.

You’re absolutely right to focus on protein. That’s the biggest lever here. Getting enough daily protein and spreading it out over a few meals makes a huge difference. Adding whey protein is a really smart move, especially on days when your appetite is low.

One thing I’d also add is carbs around your workouts. Even a small amount before or after training can help with strength, endurance, and recovery. When carbs drop too low, lifts feel heavier and rest times get longer, which sounds a lot like what you’re experiencing.

I’d also be careful not to let your calories drop too aggressively. Glp1s makes it really easy to undereat without realizing it. If the weight is coming off faster than you want and your performance is slipping, that’s usually a sign you may need to eat a bit more, even if you’re not that hungry. This I know is the challenge 😉

taurine can help a bit with hydration and fatigue, but it’s more of a support player. It won’t replace enough protein and overall nutrition when it comes to preserving muscle.

Big picture, you’re doing a lot right already. This is more about dialing in fuel and recovery than changing everything. If you get protein, a bit of carbs around workouts, and keep calories from dropping too low, there’s a good chance your strength will stabilize again over the next few weeks.
 
are you losing strenght ? between session ?

if yes you are losing muscle

i didnt eat for almost 2 week on reta (insane gi issue ) but i run trt too

i lost like 5% streangh
 
Rezwalker said:
are you losing strenght ? between session ?

if yes you are losing muscle

i didnt eat for almost 2 week on reta (insane gi issue ) but i run trt too

i lost like 5% streangh
Yeah, most notably last Friday. Had to break my circuit in the middle of the second lap for a long rest before continuing sets. Or as jfrick11 suggested, maybe just a shortage of carbs and depleted glycogen store.

I'm also now back on trt at therapeutic level thankfully. I stopped after surgery when I read a few studies that correlated trt with the tendon injury which I suffered. ChatGPT convinced me otherwise and explained how those studies were deeply flawed and that stopping trt was extremely unadvisable during recovery. Gotta love AI.

In any case, I'm making an effort to better track protein and calories and force myself to eat if necessary. This peptide is more powerful than I expected even at 1mg dose. This is my first GLP-1 and I'm apparently very susceptible to the effects
 
I wish I could fast on Reta lol, I wake up during the night and I need to snack cause my blood sugar gets too low. Crazy. Didn't have that with Tirz.

To answer OP question, I don't think it's sustainable to fast 1/7 and stay at maintenance 6/7. It's not that big of a deficit first of all, you probably need 2 days at 0 calories considering you won't be burning much over your BMR those days.

Generally you want to eat more on workout days, you wanna fuel those lifting sessions otherwise you lack strength, move less weight, and fail to preserve muscle. But you still need to get some protein in to speed up recovery on resting days.

With that said I'm a fan of strategic fasting, just every week seems a bit too much.

Also agree with having more carbs. If you need to rest for longer, it's not because you're losing strength, you're lacking fuel and possibly electrolytes.

Do you get dizzy when doing exercise that elevate your HR, for example squats/lounges?
 
It's important to know your starting point. If your body fat percentage is below 15%, I wouldn't recommend that fasting protocol, nor very low-carb diets. The key is training combined with sufficient protein, followed by carbs around your workout, and perhaps a few more meals.
 
Status
Not open for further replies.

Members online

No members online now.

Forum statistics

Threads
4,434
Messages
86,405
Members
7,877
Latest member
jhonpdr
Back
Top