I saw the scary headlines a couple of days ago. You probably did too. The one that caught my attention was this:
Diabetes expert warns paleo diet is dangerous and increases weight gain
That headline was over an article on the EurekaAlert! website. Here are the opening paragraphs:
A new study has revealed following a low-carbohydrate, high-fat diet for just eight weeks can lead to rapid weight gain and health complications.
The surprise finding, detailed in a paper in Nature journal Nutrition and Diabetes, has prompted University of Melbourne researchers to issue a warning about putting faith in so-called fad diets with little or no scientific evidence.
Goodness, no, we wouldn’t want to make our dietary decisions based on little or no scientific evidence. Luckily for us, someone conducted a rigorous and relevant scientific study before declaring the paleo diet dangerous for humans. That’s why it made such a splash in the news.
Here are some paragraphs from another article that appeared in Medical News Today online:
Scientists have warned against following celebrities into “fad” diets that are not supported by scientific evidence, as findings published in the journal Nutrition and Diabetes reveal that just 8 weeks on the “Paleo” diet can pile on the pounds and raise the risk of health problems.
Adherents of the LCHF diet consume more protein, fiber and fat than the average Western diet and less sugar and starchy carbohydrates.
Suggested “dos” include grass-produced meats, fish or seafood, fresh fruits and vegetables, eggs, nuts and seeds, and healthful oils such as olive, walnut, flaxseed, macadamia, avocado and coconut.
Foods to avoid include cereal grains, legumes – including peanuts – dairy products, refined sugar, potatoes, processed foods, salt and refined vegetable oils.
So apparently, those rigorous and concerned scientists fed people more protein, more fat, and less sugar than a standard diet and were surprised when the paleo dieters experienced rapid weight gain and health complications in just eight weeks.
Damn, that is worrisome. To think I’ve been operating under the assumption that a diet of grass-produced meats, fish or seafood, fresh fruits and vegetables, eggs, nuts and seeds, and healthful oils such as olive, walnut, flaxseed, macadamia, avocado and coconut would be good for me. I was so very, very disappointed to learn than people who spent eight weeks living on grass-produced meats, fish or seafood, fresh fruits and vegetables, eggs, nuts and seeds, and healthful oils such as olive, walnut, flaxseed, macadamia, avocado and coconut got fat and sick.
But since I’m not an idiot, I kept reading. Here are more quotes from the Medical News Today article:
Researchers at the University of Melbourne were concerned about the hazards of a paleo diet, especially for those who are already overweight and living a sedentary lifestyle and for individuals with pre-diabetes or diabetes.
To investigate, they took two groups of overweight mice with symptoms of pre-diabetes.
The mice in one group consumed an LCHF diet for 8 weeks, 60% of which was fat, compared with their usual 3% fat intake. Carbohydrates made up 20%. The mice in the control group ate their usual food.
After 8 weeks, the Paleo diet group had increased in weight, glucose intolerance and insulin. The mice had gained 15% of their body weight, and their fat mass had doubled from 2% to almost 4%.
This “extreme weight gain” is equivalent to a person who weighs 200 pounds gaining 30 pounds in 2 months.
Wowzers. So if you switch to a diet of grass-produced meats, fish or seafood, fresh fruits and vegetables, eggs, nuts and seeds, and healthful oils such as olive, walnut, flaxseed, macadamia, avocado and coconut, you could gain 30 pounds in just two months – if you’re a mouse.
Then again, I’ve seen headlines before about mouse studies that supposedly demonstrated the hazards of a paleo or LCHF diet. The scientists never seem to feed those mice grass-produced meats, fish or seafood, fresh fruits and vegetables, eggs, nuts and seeds, and healthful oils such as olive, walnut, flaxseed, macadamia, avocado and coconut.
So I took a peek at the full study. Let’s see what the researchers themselves have to say:
NZO mice were maintained on either standard rodent chow or an LCHFD from 6 to 15 weeks of age.
What the heck is an NZO mouse? Yeah, I wondered that myself. So I looked it up on the website for a company that supplies them:
NZO mice of both sexes exhibit high birth weights and are significantly heavier at weaning age. Severe obesity (including both visceral and subcuatneous fat depots) develops even when mice are maintained on a standard diet containing 4.5% fat.
I see. So we’re talking about mice bred to become obese, even on a low-fat diet.
Both males and females of the NZO/Hl substrain exhibit impaired glucose tolerance (IGT), but subsequent type 2 maturity onset (NIDDM) diabetes development is limited to males, with a phenotype penetrance of 50% or less. NZO/Hl mice also show anti-insulin receptor antibodies, a defect in leptin transport, and hypertension.
Wow, sounds just like me. In fact – amusing story here – I used to wonder why my parents, who were struggling financially when The Older Brother was born, decided to add the expense of a second child a mere 18 months later. I always assumed it was because they were Catholic and that’s what the rhythm method accomplishes: it makes more Catholics.
Eventually, I dared to asked my mom why they had me so soon after my brother. Her reply was something like, “We were very interested in biology and wanted to produce a son who would become severely obese on a standard diet and show impaired glucose tolerance, anti-insulin receptor antibodies, a defect in leptin transport, and hypertension. That was you.”
So I’m totally on board with the idea of applying the results of an NZO mouse study to me. Still, I can’t help but wonder about that diet. Let’s go back to the study:
Prior to the study, all mice were fed a standard rodent maintenance diet. At 6 weeks of age, mice were either transferred to an LCHFD or maintained on the standard diet (chow) for a further 9 weeks. The LCHFD contained 24 MJ kg−1 digestible energy (3.1 MJ or 13% coming from protein, 1.5 MJ or 6% from carbohydrate and 19.5 MJ or 81% from fat. The chow diet contained 13.5 MJ kg−1 digestible energy, with 2.7 MJ or 20% coming from protein, 9.5 MJ or 70% from carbohydrate and 1.4 MJ or 10% from fat.
I see. The standard-chow mice got a diet of 20% protein, while the “paleo” mice got a diet of 13% protein. Wait a minute … how did the Medical News Today article describe a paleo diet again? Let me go find that quote again … okay, here it is:
Adherents of the LCHF diet consume more protein, fiber and fat than the average Western diet and less sugar and starchy carbohydrates.
So the “paleo” mice consumed 35% less protein than the control group. And according to the study documents, the protein the “paleo” mice consumed consisted entirely of casein. Let’s look up the definition of that word.
A protein precipitated from milk, as by rennet, and forming the basis of cheese and certain plastics.
Yup, this is sounding more and more like a true representation of the paleo diet. That’s what most paleo dieters I know do: they precipitate milk as by rennet to isolate the casein and then eat it.
Well, at least the mouse “paleo” diet was high in fat – perhaps ridiculously high in fat, but high in fat. And I’m sure they were paleo fats. After all, as the Medical News Today article clearly stated, paleo dieters avoid cereal grains, legumes, dairy products, refined sugar, potatoes, processed foods, salt and refined vegetable oils.
So I looked up the contents of the “paleo” diet. As a percent of the total, the “paleo” mice got 54% of calories from cocoa butter, 14% from clarified butter, and 14% from canola oil.
Dangit! That is EXACTLY LIKE MY PALEO DIET! I get up every morning and swallow big globs of cocoa butter, then wash it down with clarified butter and canola oil … because it’s not as if butter (or casein) is a dairy product and canola oil is a refined vegetable oil or anything. I take my paleo seriously.
I kept reading to make sure the relative increase in fat intake for the mice was similar to the relative increase in fat for humans who switch to a LCHF diet. Here’s what the study had to say:
Rodent chow is normally low in fat (3% of energy) and high in carbohydrates (approximately 50% starch). In contrast, the LCHFD used here had a very low carbohydrate (only 6% of energy, 100% sucrose) and high fat content (81% of energy).
Just as I feared: the change is totally relevant to humans going LCHF. Compared to their normal diet, the “paleo” mice increased their fat intake by 2567%. Same here. When I switched from low-fat to paleo, the percent of fat in my diet went from 20% to 513% of total calories. I had no idea that would be bad for me — especially the canola oil.
The carb content of the “paleo” diet was low, of course. And since paleo is what it is, those carbs probably came from vegetables, maybe some tubers …
The carbohydrate content of the LCHFD was exclusively derived from simple sugar.
Wait a minute … the paleo mice got 6% of their calories (100% of the carb calories) from simple sugar? Well, I’m sure that was at least a reduction compared to the standard chow.
Typically, rodent chow carbohydrate is contributed to by 50% starch and approximately 2% simple sugars.
I see. So the non-paleo mice got 2% of their calories from simple sugars, and the “paleo” mice got 6% of their calories from simple sugars. Well, once again, that’s exactly what happens when people go on a paleo diet: they triple their intake of simple sugars. That’s why the Medical News Today article mentioned this:
Foods to avoid include cereal grains, legumes – including peanuts – dairy products, refined sugar, potatoes, processed foods, salt and refined vegetable oils.
So there you have it. Mice and men. People who try paleo diets are almost exactly like NZO mice, and the paleo diets they try are almost exactly like the “paleo” diet in this study. So if you go paleo, you’re probably going to get fat and sick. I know it’s true, because the lead researcher said so:
Lead author, Associate Prof Sof Andrikopoulos says this type of diet, exemplified in many forms of the popular Paleo diet, is not recommended – particularly for people who are already overweight and lead sedentary lifestyles.
“Low-carbohydrate, high-fat diets are becoming more popular, but there is no scientific evidence that these diets work. In fact, if you put an inactive individual on this type of diet, the chances are that person will gain weight,” Andrikopoulos, President of the Australian Diabetes Society, said.
Yup, the lead researcher is President of the Australian Diabetes Society, which (like our own Diabetes Society) has been pushing low-fat diets for years. But I’m sure that didn’t affect how he designed or interpreted the study.
And neither did the fact that (according to his bio) he’s received a lot of research money from drug companies. I mean, It’s not as if the paleo diet would reduce the need for drugs or anything.
