Please Explain: Metabolism

Friday, December 12, 2008

Some diets and supplements claim to work by speeding up metabolism. Find out how metabolism works, why it’s essential to life, and whether food, exercise, and supplements really can accelerate it...or slow it down. Dr. Rosalind Coleman is Professor of Nutrition and Pediatrics at UNC-Chapel Hill; Marion Nestle is Professor in the Department of Nutrition, Food Studies, and Public Health at NYU. She's author of several books including, most recently, What to Eat.


Dr. Rosalind Coleman and Marion Nestle

Comments [33]

Charles Fred from Maspeth, Qns

To “jawbone from Parsippany“

For some people Synthroid leads to depression-like syndromes. Your thyroid produces both T4 and T3 hormones. Synthroid is just T4, but most people make enough T3 from the T4.

My wife was treated just as you were - iodine, Synthroid. Then, for the first time in her life, she became depressed. Fortunately, I chanced upon a current medical article (below) which spoke to this problem.

Unbeknownst to her, I substituted whole thyroid (the best known brand is Armour thyroid) which contains both T4 and T3. Her depression almost immediately disappeared.

She did well for many years, until she suffered a lengthy (unrelated) stay in one of the top teaching hospitals. They gave her Synthroid, and one day, she suddenly said, “I just want to die.” She had depression.

I explained her history and showed the medical journal articles to the doctors. Since their pharmacy didn’t carry whole thyroid, they had me supply it. Her depression soon disappeared.

Your doctor can prescribe an equivalent dose of whole thyroid. There is absolutely no danger, so you have nothing to lose.

If your doctor refuses you this “everything to gain - nothing to lose” trial, he is putting his hardheadedness above your welfare. Try another doctor.
New England Journal of Medicine (America’s foremost medical journal) Volume 340:424-429 February 11, 1999
Effects of Thyroxine as Compared with Thyroxine plus Triiodothyronine in Patients with Hypothyroidism is a great source of reliable and complete info on this.

Let me know what happens.

Dec. 15 2008 02:45 PM
Tina from Queens

You should have had an Endogrinologixt and a Pharmagologist, along with a nutritionist (NOT the smug Marion Nestle!)

Dec. 13 2008 03:23 PM
Carol from Red Bank, NJ

I agree that having two nutritionists, who seems rather ingnorance of endocrinology and other areas that involve metabolism, was poor. When "Dr." Nestle dismissed potential metabolic problems arising from psychiatric and/or other drugs as arisng from from just eating too much, she is blaming the victim. I know from personal experience and from discussions with others that it is just not that simple. Re: lithium: some people do not gain wait while others do but I don't think one can just surmise that ALL of the people who do gain weight just eat too much. Another personal example: This AM I am 10 lbs heavier than I was one week ago. During the past week, I was prescribed an antibioltic and antivert due to complications from an upper respiratory infection. I am quite certain that I did NOT eat the approx 30,000 extra calories that would lead to a 10-lb weight gain.

Dec. 13 2008 11:11 AM
Stephanie from Manhattan

It's evident from the calls and the posts that there are more questions than answers on this important topic. Perhaps next time you could bring in physicians and endocrinologists who have a better understanding of the many aspects of metabolism. Many thyroid issues are hereditary, extremely complex to regulate and certainly should not be dismissed out of hand by your guests. Look forward to your next show on this subject. Hopefully it will be more enlightening than this one was.

Dec. 12 2008 09:58 PM
JLL from Westchester

I agree the comment about thyroid from the guest was a stupid one. I guess since she isn't an expert in that area she was trying to avoid the topic. I have been dealing with hypothyroidism since I was a teenager and I've been on synthroid since then. My metabolism is what I consider good and I maintain a slim waistline. However, when the thyroid is out of sorts I shoot up in weight in a short period of time. I often wonder how much of our weight does the thyroid control, it seems like a lot. I suggest that anyone with weight concerns, either over or under weight, get their thyroid checked (a simple blood test can do the trick). It is a very simple thing to correct and living with uncorrected hypo or hyper thyroidism is very stressful emotionally and sometimes physically and it can distract you from reaching your greatest potential.

Dec. 12 2008 04:22 PM
JC from Brooklyn

Re: changing your metabolism . You've heard of the infamous 10 pound gain after pregnancy. I had a permanent 10 pound loss after pregnancy. I was an extremely active new mother and I breast fed and I do believe my metabolism changed as a result. Maybe this will help other women....

Dec. 12 2008 01:56 PM
James from NYC

How can you tell what your specific caloric intake should be?


Is the BMI really worth noting?

Dec. 12 2008 01:56 PM
Fish from brooklyn

These 2 doctors answers are two simplistic. Answers like, "I am sure they do" and "I think" are good enough.

Skipping breakfast is one the worst things you can do.

Dec. 12 2008 01:56 PM
jawbone from Parsippany

I didn't realize both guests were nutritionists--perhaps an endocrinologist would also have been appropriate for discussing metabolism.

Re: thyroid--if it slows down too much or is removed entirely, people initially become very tired, get "brain fog," develop painful achiness, and, eventually, die. Very important in setting metabolism.

Dec. 12 2008 01:56 PM
Amy from Manhattan

Center for Science in the Public Interest's publication "Nutrition Action" has a sort of reverse-psychology story this month called "How to Get a Gut." It gives "8 tongue-in-cheek tips." No. 2 is "Keep eating as much as you did in your 20s." Their source says that as we age, we use fewer calories even if we maintain the same level of activity. And men require even lower calorie intake to stay at the same weight than women do.

So yeah, it doesn't just seem that way.

Dec. 12 2008 01:56 PM
KK from NYC

What a nasty rude comment on thyroid from Marion Nestle! As someone what has suffered from thyroid impairment for 20+ years, I can assure you that your comment is uninformed. Stupid comments like that are really distructive to those of us who have real medical problems arising from our thyroid. A piddly 20 pound of excess weight is NOTHING. True weight problems, myxedma, hair loss, exhaustion... those are the most obvious problem. I'm so angry at that stupid stupid woman!

Dec. 12 2008 01:54 PM
Janice Frick from NYC

I would like to address the question the woman who called regarding her husband who skips breakfast. Some important questions I would ask are - yes, he is very hungry in 2-3 hrs after breakfast, but how is his hunger and food intake later in the day? In other words how is his early afternoon hunger affecting his total caloric intake? Also is this a man who is struggling to maintain his ideal weight? And I would ask the woman who is newly into menopause and just off SSRIs what about her total calories??

Dec. 12 2008 01:52 PM
A Fisher from LIC

THere is a benefit to gaining weight when one ages. The fat gained provides a calorie battery to burn when we are old AND sick.

My father, 67, got sepsis last year and spent three weeks in hospital not eating at all. Over this time he burned all his extra fat. The fat, although he is in good shape, served him extremely well.

Dec. 12 2008 01:50 PM
Ruth from Washington Heights

I gained 20 lbs. on SSRIs - finally lost it on Weight Watchers after trying other things for a year.

Even a 50 year old. Like me. And my husband. You can stay in good shape but you MUST keep moving and try new things!

I hate to say it, but that 3 x a week thing they recommend is not true.
You have to exercise every day.

(we're adults now- we can take it.)

Dec. 12 2008 01:48 PM
nick from manhattan

im in the non breakfast person as well.. if i force myself to eat within 2 hours of getting up... ill be starving by 10 or 11. and searching for snacks again by 3!

if i eat breakfast...the catch is spacing the meals and cutting the portions.. i eat at 7am, 11am, 3pm, 6pm, 10pm

Dec. 12 2008 01:48 PM
Colleen Flannery from norwalk ct

Do whole food supplements and vitamins make a difference in achieving our goals verses the usual man made vitamins and supplements?

Dec. 12 2008 01:47 PM
anonyme from NY NY

I think this is not really a very enlightening discussion of metabolism - and i suspect when thinkers wean themselves of reductionist thought we might see how such a complex thing as metabolism actually works

Dec. 12 2008 01:47 PM
Erica from New York, NY

It seems that suggesting the Pima Indians in Arizona should avoid eating junk food is simplifying the problem of obesity in this population. Obesity is often related to poverty and the Pima Indians as many Native Americans live in poverty. The most affordable food is often calorie rich and nutrient poor. Perhaps, instead of suggesting Pima Indians should avoid junk food, we should be discussing the greater problem of access to nutritious and healthy food, for those in lower economic strata. Additionally, those who live in poverty are much less likely to have to opportunity to engage in physical activity given long work hours and lack of safe and appropriate outdoor space for exercise.

While overweight can boil down to calories, it is much more complex in a larger context.

Dec. 12 2008 01:46 PM
Michael from Manhattan

How do you guests feel about "caloric restriction" as a weight management strategy?

Dec. 12 2008 01:46 PM
Jeffrey Slott from East Elmhurst

Bagels are junk food, in my opinion. The average plain bagel is 250-300 calories! Before the butter or jelly or cream cheese, etc. I am a diabetic and I used to eat a bagel daily; I stopped years ago because of the way it would make me feel afterwards.

Dec. 12 2008 01:46 PM
John from Toronto, Ontario

a coach told me execrcise for 20+ mins. before your first meal in the morning speeds up your metabolism by 10% for the rest of the day - is this true?

Dec. 12 2008 01:46 PM
Colleen Flannery from norwalk ct

The Pima indians were a dessert dwelling people gathered desert beans(which are very tasty) and hunted they also lived near a river in which they made their livelihood as weavers from until the us government forced them into a reservation, dammed their river so it dried up, and gave them us government rations of food which were high in fat and not healthy. they were also no longer allowed to hunt in their regular territories which they had lived in for three thousand years. Maybe now they choose to eat what is easily accessible to them but diabetes most likely set in with the food and sedentary lifestyle that was forced upon them by the us government generations ago.please tell the woman who made light of these peoples "choice" of food.

Dec. 12 2008 01:45 PM
olivier from bklyn

what about undigested colon "waste"(such as meat residue)? Is it why our metabolism slow down?

Dec. 12 2008 01:45 PM
Ro from SoHo

Eat when you're hungry? Absolutely! But that requires people to be able to recognise hunger rather than habit.

I find that most peole cannot distinguish the difference or are not in the habit of asking themselves if they are indeed hungry or not. And are not able to recognise when they have satisfied their hunger during any given meal.

Dec. 12 2008 01:44 PM
olivier from bklyn

Does ones metabolism slow down invariably or am I stuck being a stick figure? Which I don't really mind other than the ever present reminders that bigger is better.

Dec. 12 2008 01:43 PM
Wendy from Brooklyn

Can you discuss the idea of "fit and fat" since the current thinking seems to indicate that it is better to get up and move, even if you maintain a higher than normal body mass, than just being slim.

Dec. 12 2008 01:38 PM
Amy from Manhattan

I thought the enzymes in saliva primarily broke down starch, not sugar--sugar's the end product. But that's from high school biology, & high school was a long time ago. Has our understanding of this changed over the last 30-40 years?

On the general theme: I once saw a T-shirt that said, "Metabolize or Die!" That about sums it up.

Dec. 12 2008 01:36 PM
jawbone from Parsippany

I have thyroid cancer and had a complete thyroidectomy (altho' not all remnant tissue was removed with the subsequent ablation treatment dose of radioactive iodine 131).

During the 3 years since my operation, I have been on varying doses of Synthroid . 100mcg for two months, utterly exhausted; 125 for 6 months, still very tired but didn't want to drop to the pavement and lie down to rest; ablation treatment 8 mos after operation, still utterly exhausted; dose upped to 150, somewhat better but still tired; then down to 137 and with that, almost suddenly, my metablolism kicked in!

I had energy to burn, I awoke before my alarm went off feeling rested, and I was losing weight without really trying beyond my lifetime of dieting! Then, when I had my annual radioactive iodine scan 10 mos later, my energy disappeared, almost overnight--weight went up, exhaustion set in, I slept through alarms, needing 10-11 hours of sleeps. I'm still in that state over almost a year and a half later.

My endo says to wait and see--tincture of time.

What is going on? Some people on my thyroid cancer chat board experience little change, some have much better energy, some are like me, with no seeming reasons. There doesn't seem to be much research on this.

What's going on? Any suggestions?

Dec. 12 2008 01:36 PM
Joe from Englewood, nj

How much of an effect does the gut flora have on metabolism?

Dec. 12 2008 01:36 PM
Greta from Manhattan

Why does metabolism slow as you grow older?

Dec. 12 2008 01:32 PM
Edward from NJ

It's my understanding that much of the nutrition we take in can only be converted to usable calories with the help of gut bacteria. Specific bacteria develop in specific populations based on the local diet. Can the guests please comment on the importance of gut bacteria to metabolism?

Dec. 12 2008 01:31 PM
RJ from NJ

Fitness gurus tell us that we burn up to 40 calories per pound of muscles. and the medical experts say it is some where between 7 to 10 calories per Lb of muscle built. which is it. i am 5 feet 2 inches tall. i lift weights, walk every day, and am very muscular, but my metabolism is very slow even with all these muscles. please tell us once and for all, can we actually lose weight by building muscles.

Dec. 12 2008 12:01 PM
michaelw from INWOOD

Is it true that building muscle on the body increases metabolism because muscle is living tissue and requires energy from the body to sustain it and fat requires nothing?

Dec. 12 2008 10:42 AM

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