200 calories below your BMR = Starvation Mode to Body?

(Davy) #1

Say I eat for 200-300 calories below my BMR (which is about 1800) and do this for say 3 days. Will the body go to so called ‘starvation mode’ and stall me out or react somehow not good? (I’ve just entered fat adapted mode and find I’m fine with my calories at this 200 calories below my BMR area. Doing Keto almost 5 weeks now; also within 11 lbs of ideal weight)

#2

Doing that for 3 days won’t make a real difference or any permanent change, BUT if you eat too far (different for everybody) below your RMR you will eventually slow down your metabolism. I did just that! Confirmed with RMR testing. Physical job, I lift and do cardio 6x/week combined and at last test I was coming in at 1700! Used to be almost 3000! At no point during many fasts or being keto for years at that point was I hungry, tired or showing any signs of my body feeling starved! I’m no longer a fan of “eat when your hungry” because of this. Hungry or not… I’m eating! It’s gotten better but still not where it should be.

(John) #3

There seems to be some evidence that chronic, day-after-day caloric restriction does lead to a slowdown of metabolism and/or increased fatigue which causes you to reduce your physical activity to match your intake.

However, it seems that periods of caloric restriction interspersed with periods of normal (maintenance level) intake reduces or eliminates this effect.

I read a great study (which I can’t find the link to now) where they took two groups of men, over a 26 week period. One group did a calorie restricted diet every day. The other group did 2-weeks of calorie restriction followed by 2 weeks of maintenance level calories. So not exactly “fast then feast” but more like “restrict and relax”.

The end result was that the 2-on, 2-off group lost more weight than the consistent reduction group, even though they ate more in total over the same time period.

I have also noticed myself that if I under-eat for too many days in a row I start feeling cold and tired, which is my body trying to conserve that energy. Whereas if I mix it up, it seems to work better.

There is some discussion I have read of just of trying to eat to your BMR (assuming you know what that is) and letting your daily deficit come from your other energy needs (exercise, activity, thermic effect of food). You could try that too.

(Windmill Tilter) #4

Three days is probably not long enough for your BMR to drop more than a fraction of a percent.

As a general rule, the longer you do it, the more it drops. The bigger the deficit, the faster the drop.

(Windmill Tilter) #5

This was the MATADOR study and it really was outstanding. Probably one of the most intelligently designed and rigorously carried out experiments in nutrition for the past decade. Unfortunately, that means it was quite expensive and probably won’t be replicated. I wish someone would though, because the results were impressive, and extremely important.

Losing 50lbs is easy; keeping it from coming back is the real war. That’s what the MATADOR study cut to the heart of. If they were right it’s a big deal.

(Michael - When reality fails to meet expectations, the problem is not reality.) #6

When I started keto I unintentionally put myself into a 1000 cal daily deficit for two months. I lost 25 pounds and never felt hungry. I stopped the weight loss by slowly upping my daily calories to 2500 and a further 10 pound loss. I do not think I lowered mr RMR during that. May be relevant that I was 71, closing in on 72 when I did this.

(Karen) #7

I’m never sure on this. If you’re in ketosis and you’re fat adapted you’re supposed to be eating your fat on your body to make up that calorie difference.

(Davy) #8

Maybe ‘eating the fat on your body’ IS starvation mode??

(Michael - When reality fails to meet expectations, the problem is not reality.) #9

I don’t like to anthropomorphize chemical processes, but… I think our bodies are a lot ‘smarter’ than we normally give them credit. I don’t mean to suggest there’s some conscious command and control center in us someplace constantly reviewing inputs, outputs and making the best decisions. What I think goes on is chemical processes follow the path of least resistance and are ‘smart’ enough to change paths in response to changes, both in resistance and response. And, of course, we can do dumb things and screw it up. You could define metabolic disease as the body’s response to being screwed up by our dumb choices. Or bad genetic luck.

Starvation. This is an extreme situation. It does not happen in a few days or a few weeks. We have evolved to deal with this in a very elegant manner. When the hunt was successful everyone ate and stored the excess energy as fat. When the hunt failed, our ancestors still had to continue hunting even when that meant days or weeks of not eating and still burning energy.

Read Scott’s diary. It’s truly extraordinary what these men endured before finally succumbing. Of course, they were not only dealing with a huge energy deficit, but an environment that necessitated equally huge energy expenditure to survive. Ultimately, they could not produce it.

Theoretically...does a 30 day fast lower bmr?
(Bunny) #10

I would experiment with that more, maybe restrict chosen calories in time frames then eat normal.

3 day on, three days off.

Keep the metabolism stimulated into oxidation mode rather than trying to horde resources?

Metabolism is expecting to do a thing long before you feed it an amount of fuel?

I always think of BMR/RMR/DEE in terms of thermal dynamics (electrical), chemical and mechanical, if know how to manipulate all three through one conduit, then you control the processes.

#11

As I understand it after a few days your body begins to adjust one way or the other. I’m pretty sure Steven finney did a study on that. Calorie deficits slow your BMr whether due to eating shortage or eating exercise shortage

(Keto Koala 🐨) #12

I’m also eating at a deficit of about 1000. I don’t feel hungry though. I eat until I’m satisfied. My Mother did Keto 3 years ago but she got waaaaay too obsessed. She started of eating great but as she lost weight she became addicted to seeing the number on the scale drop and 4 months after starting got down to 105 pounds from eating a tiny 500 calories a day. I only made it to 900 calories today but I ate until I was full. Wasn’t trying to have low calories it just happened. Plus it’s hard to eat in this heatwave in Australia.

#13

nah. eating your muscle tissue is starvation mode

actual fat used is stored fat for energy when needed.

also while the fat is used, that fat releases stored toxins in it so if we have big weight drop fast we can feel icky while it is happening.