Does the Paleo Diet Cause Weight Gain? Examining the study that claims so.

You might have seen the headlines.

“Popular ‘Caveman’ Paleo Diet is Labelled Dangerous by Health Experts!” screams the Sun.

“The Paleo diet is ‘dangerous and increases weight gain’, diabetes expert claims” headlines the Daily Mail.

Sigh.

Boy, do they love to sensationalize.

Here’s what really happened: there was a study done on overweight, pre-diabetes mice, where they were fed a “low carb, high fat” diet and somehow ended up gaining weight. Not only that, but the mice developed health problems. Their insulin levels rose and their glucose intolerance worsened.

Doesn’t sound too much like the Paleo diet, does it?

Well, turns out there are a lot of problems here.

1. “Low Carb, High Fat” does not equal Paleo

Despite what the clickbait headlines want you to believe, the mice in the study DID NOT eat a Paleo diet. In fact, their diet wasn’t even remotely similar to the Paleo diet.

Check out the table below, taken directly from the study. On the left is the diet the mice in the “Low Carb, High Fat” group were fed:

Sucrose? Casein?! Canola oil?! Oh my, no wonder those mice ended up in worse condition than they started.

It appears the “Low Carb, High Fat” diet was designed to make the mice sicker. Casein, for example, is known to cause cancer in mice. It’s also one of the main reasons dairy is not part of a Paleo diet. And they used casein as one of their main sources of protein for the mice!

The “high fat” part of this diet came mostly from highly processed oils, which would never be part of a true Paleo diet.

It is clear that although the diet given to these mice was, indeed, low carb and high fat, it was nothing like the Paleo diet. There are many different ways to eat low carb and high fat – not all of them are healthy.

The Paleo diet specifically focuses on healthy fats and only certain, highly nutritious carbs. Sucrose would never be the #1 source of carbs in a true Paleo diet!

2. Control group got a much more vitamin-rich diet

Not only were the mice in the “low carb, high fat” group fed processed junk and wood pulp, they also didn’t get the same vitamins that the control group got.

The control group enjoyed a wide variety of vitamins as part of their “regular chow” diet, which were, for some reason, completely lacking in the test group (aside from a bit of pre-mixed rodent “vitamin mix” which consisted of a much narrower variety of vitamins and for some reason contained soy… um totally not Paleo).

When comparing two different groups in an experiment, wouldn’t you want all factors to be the same aside from the dependent variable? In this case, the dependent variables would be the carb and fat sources in the diet, not the vitamins.

Without doubt, the difference in the amount and variety of vitamins and minerals helped the control group retain better health than their less fortunate counterparts.

3. There are plenty of real scientific studies suggesting that the Paleo diet works

The lead author of this embarrassing piece of work, Associate Professor Sof Andrikopoulos, claims:

‘Low-carbohydrate, high-fat diets are becoming more popular, but there is no scientific evidence that these diets work.

No scientific evidence? Maybe no sloppy scientific evidence like what he’s used to, but there are actually plenty of studies that suggest that healthy low carb and high fat diets, such as the Paleo diet, work.

What’s even better, those studies were done on actual people, not mice. And they were fed an actual Paleo diet, not a pathetic mix of sucrose and canola oil.

Check them out:

• Osterdahl M, et al. Effects of a short-term intervention with a paleolithic diet in healthy volunteers. European Journal of Clinical Nutrition, 2008. Conclusion: individuals lost weight.
• Jonsson T, et al. Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovascular Diabetology, 2009. Conclusion: Paleo diet caused weight loss and improvements in cardiovascular health.
• Frassetto LA, Schloetter M, Mietus-synder M, Morris RC, Sebastian A. Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. Eur J Clin Nutr, 2009. Conclusion: even short-term consumption of a paleolithic type diet improves BP and glucose tolerance, decreases insulin secretion, increases insulin sensitivity and improves lipid profiles.
• Ryberg, et al. A Palaeolithic-type diet causes strong tissue-specific effects on ectopic fat deposition in obese postmenopausal women. Journal of Internal Medicine, 2013. Conclusion: the test group exhibited weight loss, major reduction in liver fat, and improved health markers.
• Lindeberg S, et al. A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease.Diabetologia, 2007. Conclusion: the Paleo diet led to greater improvements in weight and glycemic control compared to the Mediterranean diet.

This last one is especially interesting, since the author of our low carb, high fat study specifically pointed out that he recommends the Mediterranean diet as a healthier alternative to Paleo.

I think we’ve seen enough evidence that he’s not only a sloppy scientist, but also quite the liar.

Take it with a grain of salt

It’s a good idea to take all new studies with a grain of salt, especially when the media seems to jump on them with such vigor. This one poorly-done study, which had nothing to do with the Paleo diet, resulted in at least a dozen alarming news articles all screaming that the Paleo diet is a sham.

Journalists are not scientists. They do not take the time to examine a scientific paper. Although they should. But instead, they are looking for a story, something that can cause a little bit of controversy and get shared a few times on social media.

They will make wild connections, assumptions, and absolute statements even when it is completely misleading to do so.

So don’t worry, my friends. Your Paleo diet will not make you gain weight or develop health problems. Keep on eating that bone broth and don’t believe every article you read!