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2007/04/05, 09:49 AM
I was reading up on starvation mode as so many people (myself included) go this route when they start losing weight. Found this article with links to lots of studies on the subject, the weights and so on are the author's not mine.
Hope this helps someone!
Jon
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First, what is starvation mode? I found this direct answer on netwellness.org --
A starvation diet does not mean the absence of food. It means cutting the total caloric intake to less than 50% of what the body requires.
Using myself as an example, my current weight is 183 lbs. and my bmr is 1450. So, I would have to cut my calories to below 725 per day. However, if I were at my goal weight of 109 lbs., my bmr would be 1129, and so I would have to cut my calories to below 565 calories.
Many fear that going into starvation mode will drastically reduce their metabolic rate and cause them to hoard calories and gain weight instead of losing.
This is not borne out by the infamous Minnesota Semistarvation Study (1950), 36 young, healthy, psychologically normal men while restricting their caloric intake for 6 months. Their calories were restricted in various phases, but the least amount of calories they were allowed was 50% of the "normal" maintenance calories. Notice, this was dubbed a "semi" starvation diet.
Yes, their metabolic rates were significantly lowered -- to something like 40% below baseline. Yet at no point did the men stop losing fat until they hit 5% body fat at the end of the study.
Lyle McDonald explains it this way:
In general, it's true that metabolic rate tends to drop more with more excessive caloric deficits (and this is true whether the effect is from eating less or exercising more); as well, people vary in how hard or fast their bodies shut down. Women's bodies tend to shut down harder and faster.
But here's the thing: in no study I've ever seen has the drop in metabolic rate been sufficient to completely offset the caloric deficit. That is, say that cutting your calories by 50% per day leads to a reduction in the metabolic rate of 10%. Starvation mode you say. Well, yes. But you still have a 40% daily deficit.
And then he follows with the note about the Minnesota men still continuing to lose fat even thugh their metabolic rates had dropped to 40% below baseline. He says, further, that no study that he's aware of where people were put on strictly controlled diets failed to acknowledge weight or fat loss.
http://www.thefactsaboutfitness.com/research/lyle.htm
Did the Minnesota men suffer negative consequences from the experience. They most certainly did, and, interestingly, many of the same consequences that anorexics experience. You can read all about the various negative consequences at this site and the implications for EDs.
http://www.possibility.com/epowiki/Wiki.jsp?page=EffectsOfSe miStarvation
Another starvation study was done in England, at Cambridge University, to determine the different effects starvation had on lean people versus obese people. It's findings are quite relevant to our discussion. The entire study is found at http://www.unu.edu/unupress/food2/UID07E/uid07e11.htm.
Does starvation mode slow down the metabolism? No, and Yes.
In the first 2 days of starvation, there is a small absolute increase in BMR relative to values obtained from overnight fasting. Overnight fasting is what every one of us does during our sleeping hours.
So it is not true that going below recommended calories for one day is going to slow down your metabolism -- quite the contrary, it may speed it up just a little.
Does Starvation mode cause our bodies to catabilize (devour our muscles and other lean mass)? Yes and No.
Lean individuals lost great amounts of fat-free, lean tissue during starvation, but obese individuals lost much more fat tissue. Obese individuals have a mechanism that conserves lean mass and burns fat instead. In the study, an example of a lean subject studied after death from starvation: it can be deduced that loss of body fat accounted for 28-36% of the weight loss and fat-free mass 64-72%. In obese individuals, the proportion of energy derived from protein (Pcal%) is only 6% compared to 21% in the lean individual. More than half the weight loss in the obese is fat, whereas most of the weight loss in the lean individual is fat-free mass.
And the loss of lean mass is not as critical to the obese person as to the lean person simply because an obese person has more lean mass than a person of the same age and height but normal weight.
Grossly obese individuals (FORBES, 1987; JAMES et al., 1978) may have over 30% more fat-free mass than lean individuals of the same height. In the example shown in Figure 3, the obese individual weighting 140 kg has a fat-free mass that is 29% greater than the 70 kg man. Obese individuals appear to have more muscle and bone than lean individuals, and these help support and move the excess body weight. Obese subjects have large vascular volumes and larger hearts, which are necessary to pump more blood around larger bodies, especially during weight-bearing activities. Obese individuals may also have visceromegaly (NAEYE and ROODE, 1970).
But when you think about it, doesn't that make fat storage sense? Why would our Maker create us with the ability to store fat if it couldn't sustain us and preserve our lean mass in cases of extreme want?
So the effects of a starvation diet upon a normal weight teen would be substantially more devastating than to me, a morbidly obese person.
Now, if the above gives anyone "permission" to undertake a starvation diet, I recommend remedial reading classes.
My opinion is, you should not go below your goal weight maintenance calories to lose weight, and you should do adequate research and dietary analysis to ensure you are getting the best nutrition you can for your calories.
If reducing your calorie intake to goal weight maintenance creates greater than 1000 calorie a day deficit, then I strongly suggest that you do a value half-way until you have lost some of your weight.
Now some advice for those unfortunate individuals who are suffering from EDs or who have foolishly ventured into starvation dieting. This comes from http://www.netwellness.org/question.cfm/28515.htm
Question:
Hi, I`m a RD. Have a client that is in the starvation mode. Know your are supposed to not change amount of calories consumed but help them to eat differently. Not sure what this means. Not had a client like this in past. Also, know it will take ~ 6 months for this client regain an appetite. Client states not hungry. I`m out in an area with not a lot of access to information. Hope you can help me to help them. God Bless
Answer:
Thank you for your question. Many people think that starving themselves will lead to fast weight loss. A starvation diet does not mean the absence of food. It means cutting the total caloric intake to less than 50% of what the body requires. The body responds by using its own reserves to provide energy, and these reserves are not just the body`s extra fat. Initially, glycogen stores are broken down for energy. Glycogen is the storage form of carbohydrate in our body. There is little glycogen available so this energy source is depleted during the first hours of starvation. When glycogen is used, water is released which is noticed as a drop in weight on the scale. These labile stores are quickly replenished when feeding is resumed which is noticed by an increase in weight.
The individual`s initial weight when starting a starvation diet will dictate to what extent fat is lost. Those individuals who are not obese (Body Mass Index (BMI) < 30) will tend to lose their lean body mass more easily and quickly than those who are obese (BMI > 30). It is dangerous for these smaller individuals to go on a starvation diet because the lean mass that is lost may come from organs such as the heart. In the 1970`s there were several deaths resulting from starvation-type diets. Death is a rare side effect, though.
The more common problem resulting from starvation-type diets is the resultant weight regain. Weight is typically regained because there has not been a change in the lifestyle that led to the original weight gain. When the starvation diet is ended, the individual returns to the same old habits. The scale will indicate the weight regain, but it will not identify the composition of the added weight. When weight is regained, it is fat. When fat replaces the muscle mass that was lost during starvation, the metabolic rate (the number of calories needed to maintain the current weight) is decreased. The frustrated individual typically initiates another starvation-type diet only to continue this cycle.
To help an individual break this cycle, begin with a diet history, and help the client make some small changes. The goal should be 4 - 6 small meals/snacks that result in a balanced intake. Also get the patient started exercising. Weight training will be important for rebuilding the lost muscle mass. Increasing muscle mass and increasing aerobic exercise will help increase the appetite appropriately. Don`t forget to help the client identify a realistic weight loss goal. That goal should never exceed 10% of initial weight in a six-month period. After six months, the client should try to maintain the loss for a few months before considering further weight loss.
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