Effects of consuming a high carbohydrate diet after eight weeks of exposure to a ketogenic diet

http://www.nutritionandmetabolism.com/content/6/1/46

Huh... it's saying the KD diet rats were fatter before the switch.

It looks like they're saying the rats gained weight on the KD diet. Strange.

Maintenance on a ketogenic diet: voluntary exercise, adiposity and neuroendocrine effects Comes from the same lab and one of the researchers is the same.

Background:
Adherence to low-carbohydrate, ketogenic diets (KDs) has been associated with greater weight loss in the short-term than low-fat, calorie-restricted diets.
However, consumption of KDs may result in decreased voluntary exercise and thus render long-term weight loss and maintenance of weight loss difficult.
Methods:
Rats were maintained on either a non-ketogenic chow (CH) diet or a low-carbohydrate, KD for 6 weeks.
Half of each dietary group was sedentary, whereas the other half was given access to a running wheel.
Running wheel activity (total distance and meters per minute), plasma leptin and insulin, adiposity, and hypothalamic mRNA for neuropeptide Y and proopiomelanocortin (POMC) were measured to assess activity-related effects in animals maintained on KD.
Results:
With access to a running wheel, rats on KD engaged in similar levels of voluntary activity as CH rats and both dietary groups decreased caloric intake.
Caloric intake increased over time such that it was significantly greater than sedentary controls after 1 month of access to the wheels, however body weight remained decreased.
Sedentary rats maintained on KD had increased adiposity and plasma leptin levels and decreased hypothalamic POMC mRNA, as compared to sedentary CH rats. KD rats with access to a running wheel had similar levels of adiposity and plasma leptin levels as CH rats with access to running wheels, but significantly increased POMC mRNA in the arcuate.
Conclusion:
We demonstrate that maintenance on KD does not inhibit voluntary activity in a running wheel.
Furthermore, prevention of KD-related increased adiposity and plasma leptin, as measured in sedentary KD rats, significantly increases levels of the anorexigenic neuropeptide POMC mRNA.

But do remember rats didn't evolve a gall bladder to deal with a 55% diet of fat, even if it was mainly lard but with a bit of soybean oil.
Pity they didn't include any omega 3?

Also remember that a rat brain only has a limited requirement for ketones. They don't have a highly developed astrocyte structure that controls blood flow through the brain and supplies neuroprotective ketones to neurones. Our astrocytes are highly developed and outnumber neurones 10 to 1. It's very wrong to imply that how rat brains respond to a KD may also apply to Human brains.

PS In my experience I managed a KD for six months from January 2008. I did not increase the limited amount of exercise I am able to sustain. I lost weight did not regain it. I wasn't stupid enough to try eating bread/cakes/biscuits or starchy carbs again.

I do regain weight it I drink beer or wine. But IF shifts it.

We don't know what the rats ate before this first one week washout period. The ketogenic diet lowered insulin levels compared to the chow diet-- at the very end of the eight-week period, before the ketogenic diet was switched to chow. If it took eight weeks to get a significant decrease in insulin from the ketogenic diet, then logically a one week washout period where the rats ate chow simply isn't long enough.

Supposedly, the chow-fed rats weren't going through a dietary change at all. So why did leptin go up so much for the chow fed rats at eight weeks, compared to week one? And why are ketones six times (or so) as high at 8 weeks vs 1 week for these rats? Ketones never get as low as they are in week one, for either group.



They should have checked. They took no "baseline" measurements for hormones, etc? Come on.