Some people actually make a conscious choice to permanently restrict their calorie intake below their Active Metabolic Rate (AMR) in the hope it will increase their chance to live longer. Such an approach is always based on a very nutrient-dense diet - those following this type of diet pay particular attention to the micronutrients and essential fatty acids & amino acids required each day while carefully controlling their calorie intake.
I personally am not convinced such an approach will increase longevity because of the calorie restriction. I am, however, open to the idea that such an approach can increase lifespan due to the nutrient-rich nature such a dietary lifestyle demands.
But, I'm not writing about this approach today because of the potential longevity...nope, today we're going to take a look at what happens when someone cuts calories over a long period of time. Specifically, how their weight loss stops!
The Post-Gazette today republished an article from the Wall Street Journal - Health Journal: The science behind starvation diets - that provides an overview of this dietary approach. Within the article is something of interest to anyone considering various diets for weight loss:
More-serious calorie restrictors reduce their daily caloric intake by as much as 40 percent. For instance, a six-foot, moderately active, 180-pound man normally would eat about 2,640 calories a day. If he practices calorie restriction, his daily calories could drop to just 2,370 or all the way down to about 1,585. Although people who practice calorie restriction, typically lose weight at first, eventually their body and metabolism adjust and the weight loss stops, despite the low calorie level.
Read that last sentence again! Eventually their body and metabolism adjust and the weight loss stops, despite the low calorie level.
Now how many times have I said this?
I bring it up again because the message you hear from the weight loss "experts" remains to "eat less and move more," even in the face of mounting evidence that such an approach is counter-productive in the long-term.
Do you really need to eat less calories to lose weight? Yes...but, you have to be careful that you do not restrict your calorie intake too much, otherwise you risk the prospect of halting your weight loss because you're not eating enough calories each day. I know that sounds so counter-intuitive, but the evidence supports the notion that you can eat too little and sabatouge your weight loss over the long-term.
This is something the "experts" repeatedly fail to tell you as they promote cookie-cutter calorie intake recommendations, most often 1400-1600 for women, and 1600-1800 for men trying to lose weight. These low calorie levels are often too low and provide too few essential nutrients! So in your effort to lose weight, you're actually giving your body a double-wammy - too few calories and too few essential nutrients!
Just to give you an idea of how counter-productive long-term calorie restriction can be, take a look at the data we have from a seven year study published last month in JAMA, that I wrote about in Seven Year Study of Low-Fat, High-Carbohydrate Diet. Over the seven year period of this study, participants reduced their calories (without being told to do so) from an average of 1788/day to just 1445/day. What happened? Nothing more than two-pounds of weight loss over the seven years! Their BMI at the start of the study was 29 and when the study ended their BMI remained at 29.
If that doesn't make you think twice about cutting calories, maybe another study from JAMA will help you understand how calorie restriction fails - Atkins, Ornish, Weight Watchers & Zone Study - that I penned earlier this week also highlights the failure of calorie restriction. The researchers didn't bother to note the dismal results of the calorie restriction and instead focused on the inability of participants to remain dedicated to their assigned diet.
And, let's not forget the data from the National Weight Control Registry! I've written about this particular study on a number of occassions, mostly to point out the very low calorie intake of those trying to maintain their weight - they average just 1400-calories each day and exercise intensely on top of that!
Is there a better way?
The way to lose weight effectively and keep the weight off requires that you fulfill two metabolic requirements - you must meet your micronutrient requirements and you must not starve your body of the energy it absolutely must have to function each day without thinking you're living in a state of famine. If your body perceives "famine" it will do all it can to conserve energy to survive long-term - put simply, it will work hard to keep as much stored energy on your body as possible so it can continue to survive until the famine is over.
If you're overweight or obese, odds are high that you are consuming too many calories each day. To lose weight doesn't mean you must radically cut your calories to lose weight - what you really should strive for is a calorie intake that is appropriate for your normal body weight and then let your body slowly return to a normal weight with the calories it actually needs instead of the excess calories you're presently consuming.
Radical idea? Not really - if you put it into a perspective of where you want to be versus where you are right now. Let's say, for arguement sake, you weigh 250-pounds and are a woman who is 5'5" tall. If someone measured your calorie intake during the day, they may find you're consuming 2,800-calories each day. Shocking, isn't it?
Now, consider that a normal weight for your height is about 155-pounds - you want to lose the extra 95-pounds and are trying to figure out how many calories to eat. If you look to the "experts" you'll be restricted to 1400-1600-calories each day, but if you look to your normal weight calorie requirements instead, you'll eat 2,000-calories each day without risking "starvation mode." You could even start by eating 2,200-calories each day and still lose weight!
You simply do not have to starve yourself or your body to lose weight! And, if you take an approach that has a more balanced calorie intake - a calorie intake guided by your normal weight rather than a cookie-cutter, one-size-fits-all calorie recommendation, your odds are high for success and long-term maintenance!