I feel that this is a pretty significant post, tying some things together that I haven't seen anywhere else. Earlier, I was reading through this paper, that speculates that Vitamin D deficiency is the cause of common obesity. I think the paper is on the right track, but it doesn't go far enough.
Before I make my argument, I need to make some other points. If you look at different variables, you see seasonal variations. First, there is a seasonal variation to inflammation. Second, there is a seasonal variation for testosterone in men. Third, there is a seasonal variation in body fat. And of course, there is a seasonal variation in Vitamin D status, barring supplementation. In all these studies, the negative results are highest in the winter and lowest in the summer.
In the paper I initially cited above, the author feels that a lack of Vitamin D is connected to all of these conditions. The idea is that the body senses less sunlight via internal Vitamin D levels and shifts into winter metabolism. Winter metabolism is equivalent to the metabolic sydrome. Therefore, obesity results when a person is in a continual winter metabolism.
I think this argument is mostly correct, but it doesn't go far enough. If you look at diet and inflammation, you start to see some other connections. Specific types of fruit, like citrus fruit and berries, lower inflammation. Of course, fruit is only naturally available in the summer time.
Next, you see that flavonoids and phytochemicals in plant food also lower inflammation (here and here). So what causes the development of flavonoids and phytochemicals in plant food? Sunlight (see here and here).
Here's my thoughts: in Paleolithic times, less sunlight in the autumn triggered the winter metabolism. This led to a whole host of things – accumulation of body fat, declining hormone levels, increased inflammation, etc. These are all things that are associated with the modern metabolic syndrome.
In the springtime, these conditions began to naturally reverse themselves. However, this was due to an increase in sunlight AND an increase in anti-inflammatory plant foods that became available.
You can even take this further and look at how certain plant foods protect the skin from sun damage. This new study shows that foods containing phytochemcials and polyphenols (which are generated from sunlight) appear to protect human skin from sun damage.
In modern times, people can get trapped in a permanent winter metabolism due to lack of sun exposure and lack of plant food in their diet. What is supposed to be a transient state of the metabolism for a few months becomes a permanent condition. You also have children now being born with a "winter metabolism" due to poor maternal diets.
To escape this cycle, people need sun exposure and these plant foods that contain flavonoids and phytochemicals. As I talked about in a previous post, I'm not sure if Vitamin D supplements are equivalent to sun exposure. In the wintertime, people may want to use phototherapy or even tanning beds to increase Vitamin D levels. Combining this with anti-inflammatory plant foods may allow a person to break out of the metabolic syndrome.
Not sure if you saw my tweet, but really hope you take this over to Whole Health Source. It’d be great to add this into the discussion going on re fat setpoint.
From my read over there, it seems that you would have to add at least one thing to escape the cycle, and that’s avoid modern foods that seem related to metabolic syndrome: industrial fructose (what’s not found in fruit), refined veggie oils, and one or more grains (Stephan’s not a fan of wheat).
Taubes talks in his video lecture re activity and obesity in migrant farm workers (who presumably are getting lots of sun!). Are they obese just due to lack of phytonutrients? Or lack of those and a whole slew of omega 6s and fructose from a cheap fast food diet?
You should read the book “Lights Out” it has a lot of similar ideas.
Matt,
Amazing!
As you know I live in a semi tropical climate…Winter metabolism applies to many people I know and see even here…because they don’t go out in the sun. Very DISTINCT difference between the “outside people” vs. the “inside people” that live here.
Marc
Fantastic insight, Matt. I think you’re spot-on with this.
Its very interesting hypothesis ties allot of stuff together but also sounds has an element of just so story to it I think it would be mistake to believe in such broad reaching hypothesis without looking looking for allot of supporting evidence.
I read that book years ago. I thought it was a very good book.
I thought about the Taubes connection as well. I have a related post coming up.
You’re right – at this point it is only a hypothesis. I will present some more evidence in future posts.
Somebody posted this at the active low carb forum; I think it fits your winter theme really well;
http://www.nature.com/oby/journal/v18/n3/full/oby2009312a.html
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This study investigated the effects of mild calorie restriction (CR) (5%) on body weight, body composition, energy expenditure, feeding behavior, and locomotor activity in female C57BL/6J mice. Mice were subjected to a 5% reduction of food intake relative to baseline intake of ad libitum (AL) mice for 3 or 4 weeks. In experiment 1, body weight was monitored weekly and body composition (fat and lean mass) was determined at weeks 0, 2, and 4 by dual energy X-ray absorptiometry. In experiment 2, body weight was measured every 3 days and body composition was determined by quantitative magnetic resonance weekly, and energy expenditure, feeding behavior, and locomotor activity were determined over 3 weeks in a metabolic chamber. At the end of both experiments, CR mice had greater fat mass (P < 0.01) and less lean mass (P < 0.01) compared with AL mice. Total energy expenditure (P < 0.05) and resting energy expenditure (P < 0.05) were significantly decreased in CR mice compared with AL mice over 3 weeks. CR mice ate significantly more food than AL mice immediately following daily food provisioning at 1600 hours (P < 0.01). These findings showed that mild CR caused increased fat mass, decreased lean mass and energy expenditure, and altered feeding behavior in female C57BL/6J mice. Locomotor activity or brown adipose tissue (BAT) thermogenic capacity did not appear to contribute to the decrease in energy expenditure. The increase in fat mass and decrease in lean mass may be a stress response to the uncertainty of food availability.
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The calorie restriction should have been insignificant. The perception of a limited food supply caused a switch in metabolism in preparation for more scarcity. Perceived scarcity. For these mice, having food around that they could have eaten, even though they didn’t want to, was slimming.
A lot of nuts and seeds ripen in the fall, maybe in some species omega 6 fatty acids are a sign that it’s time to fatten for winter?
I don’t know if this is the right focus for the problem of obesity. Anecdotally, I come from northern Norway where we have no sun at all during 2 months of winter (20th of November to 20th of January), and it’s quite dark from October to mid-February as well. Actually, throughout winter the sun is at an angle where we get practically no vitamin D at all.
How this affects our health overall, I do now know, but I know that obesity was very rare when I was growing up and still is relatively rare. Like everywhere in the west, however, obesity is on the rise now. What has not changed since I was young are the movements of the sun and the earth… what has changed however is that people eat more candy and drink more sodas and eat more potato chips and other snacks.
The vitamin D we get from eating fish in winter and drinking cod liver oil is not a lot compared to what you get in the sun, and a lot of people don’t eat fish and most don’t take cod liver oil.
I think there are more fruitful areas in which to search for the ‘mystery’ of obesity than vitamin D.
Excellent point about omega-6 in the fall. I will post about this.
If this theory is true, seems populations that live closer to the equator but still eat Western diets generally less obese than other populations. At least, that would be my gut reaction.
What an interesting post. Although I’m not looking at it from the obesity angle, but rather the autoimmune one. I’ve had autoimmune issues my whole life which turned out to be Celiacs and Crohn’s and my son, age 4 has always had gi issues (and came down with autism at 18 mos has made miraculous progress on the SCD diet. While we are both the ideal diet responders, we still are not 100 percent in the winter. I have always felt better in the summer and my son struggles with constipation in the winter. I wonder if this has something to do with it. I know there’s suppose to be more vitamin D defficiency on Crohn’s. I’m curious to see what else you find on winter metabolism.
lots of things have changed since the past, one our food is processed more, longer storage which may decrease nutrints, and sun avoidance without sunscreen and low quality carb intakes that lack calcium fat soluable vitamins and phytochemicals like white flour and their constituents and low fat dairy consumption. second people believe in food myths of fat is bad carbs are good, what they fail to see is that quality carbs are good like fresh fruit and veggies and the wholest whole grain you can get and beans. not soda pop and potatoe chips and other junk. while they wont hurt you occassionally, some drink pop like it is water.
people also are trying to use portion control to control weight which fails in the long run and since they are desperate to lose weight especially if obese they don’t know any other way but to restrict calories. so they yo yo because they dont know any better way.
I speak from experience, so when I read researchers talk about the winter metabolism, which makes so much sense to me, I listen up, cr doesn’t work, neither does forcing it off via exercise. if your going to cure obesity you have to know why people get obese, you have to look at the physical causes and stop looking at the pyschological or moral causes.
our bodies are trying to tell us something, our diets are crap, our nutritional status is bad, we keep dieting for weight loss which makes your nutritional status even worse triggoring the body’s defenses making your fatter, more tired and disgusted. I think there is a better way to address obesity or just plain live then this misery.
rosa