Starvation mode with too much exercise?

shell1005 wrote: »

Starvation mode is a myth.

However if you are engaging in a lot of exercise, I personally recommend eating half your calories back to properly fuel your workouts and not risk increased loss of lean muscle. It's also going to combat some exercise and diet fatigue with the additional calories.

I typically eat all my calories back and I've already dropped over five pounds in less than three weeks.

Even that is debatable...
My BF% is in the single digits I am quite certain.....and keep it there for a while over the course of the summer.....

So metabolic damage is highly suggestive.

Your body responds properly to what it is given.

It's possible. I just remember the last time I followed one of these threads there was mention of a study done many years ago, as I recall, of men that they intentionally ran into very low body fat percentages. I don't remember the details anymore.

Interesting study.
I would love to see them do a similar study where they had the subjects (a portion of the people) partake in resistance training over the course of their weight loss.

I have wondered the same thing. I wonder if it possible to negate the metabolic slowdown of skeletal muscles by forcing them to work.

But the study was about what happens when you simply lose fat.

With this study it just seems that they had the subjects diet and not do anything to maintain muscle during the process....so of course their energy requirements would also go down, and as such their likeliness to put back on weight would be great. As well as it getting harder for them to lose weight......
Because when they put back on the weight, it would be fat and not muscle.....so as I stated earlier, there is no energy demand to maintain fat stores like there is to maintain muscle.

The energy requirements go down not just due to loss of body mass, but beyond that. In other words it's not just because you got smaller (obviously the smaller you are the less calories you need). They found that your metabolism will be 10%-15% less than someone of similar body composition who had never been obese.

Please find me a study where Leibel didn't draw his data from patients who had lost weight on DRASTICALLY low calorie intakes.

I'm not aware of any. But as I understand the study the conclusion is that it is the loss of Leptin that triggers the response, not the caloric intake (obviously the caloric intake is what is causing the reduction in fat, though). They know this because they were able to mitigate the symptoms using Leptin replacement therapy.

The claims you're making from that study go against the actual experimental results of the Minnesota starvation study. The participants in that study all recovered their metabolic rate within a short window of returning to maintenance.

I assume by "returning to maintenance" you mean at the end of the rehabilitation period? I have not read the entirety of the Minnesota study, but presumably the participants ended up back at their starting weights at the end of the rehabilitation period.

Once your fat levels return to their previous levels, Leptin levels return to their previous baseline and the metabolic slowdown goes away.

You're also misquoting what the study says:
"The pre-eminence of NREE - accounting for as much of 85–90% of the decline in TEE below predicted values in weight-reduced subjects 20, 22". That means most of the change in calories isn't your body turning on some hidden efficiency switch - it means your body is turning on a "hey, let's not do so much stuff" switch.

See the next paragraph after that one:

"Studies of skeletal muscle chemomechanical efficiency (calories expended above resting per unit of power generated) in weight-reduced subjects indicate that maintenance of a reduced body weight is associated with an approximate 20% increase in skeletal muscle work efficiency at low levels of exercise, whether measured by bicycle ergometry or 31P-NMR muscle spectroscopy 20.

...

Both of these methods demonstrate that the maintenance of a 10% reduced body weight is associated with an approximate 20% increase in skeletal muscle chemomechanical efficiency and an approximate 18% relative increase in the fractional use of free fatty acids as fuel during low level exercise 20, 27 (see Table 2)."

Basically your skeletal muscles get about 20% more efficient and this results in about a 10%-15% overall reduction in metabolism.

Right I get that.
That is why I was wondering what the impact would be if the person had done something to maintain or increase muscle mass during the process vs. simply losing fat.

I just caught this part:

"Studies of skeletal muscle chemomechanical efficiency (calories expended above resting per unit of power generated) in weight-reduced subjects indicate that maintenance of a reduced body weight is associated with an approximate 20% increase in skeletal muscle work efficiency at low levels of exercise, whether measured by bicycle ergometry or 31P-NMR muscle spectroscopy 20."

I don't know what would happen with high levels of exercise.

If you look in the paper, that's misquoting. They said 85-90% of the change in calories is NREE (Non Resting Energy Expenditure). That isn't metabolic damage or adaptation, that's losing weight and feeling like moving less.

Yes, 85-90% of the change in calories is just due to getting smaller.

It's the 10%-15% that is due to the body's response to fat loss. That is the thrust of the study.

That's why when an obese person loses body fat to end up with the same body composition as someone who was never obese, their metabolism will be 10%-15% less than the person who was never obese.

They are both the same size, but the formerly-fat person will have a lower metabolism. It's the body's response to lowered Leptin levels.

So that would be next to no exercise/resistance training?

That's what I'm gathering, but I could be wrong.

Muscles being 20% more effective wouldn't result in a 10-15% total reduction though. Because most of your metabolism has absolutely nothing to do with your muscles.

I'll have to go find the quote again, but that's what they said. They said that most of the 10-15% total reduction was due to the increased efficiency of the skeletal muscles.

PPumpItUp wrote: »

If you let your calories drop beyond a certain point for a certain amount of time, your metabolism shuts down. I was wondering, if I keep my calories at a healthy level but do a lot of cardio and weight training, burning enough calories to put me at a low net calorie count for the day, will my body enter its starvation mode and slow my metabolism?

personally, i'd worry more about whether I was getting adequate nutrition for exercise recovery and performance. you have to be particularly careful in a cut not to underfeed if you're doing a lot fitness wise...underfeeding will seriously lead to some recovery issues and ultimately injuries.

So again, they did no exercise.
Where had they, it would have benefited them.