Does the Paleo Diet Actually Cause Weight Gain? (What the Researchers Did to Get that Result Will Shock You)

Can you really gain weight eating salmon and fried eggs?

The latest study on the Paleo Diet coming out of Australia is sending shock waves through the media here in the U.S.

Reporters are tripping all over themselves trying to get the word out that a Paleo Diet, defined by the researchers as a very low-carb high-fat diet, causes weight gain even though the Paleo Diet is NOT a low-carb, nor high-fat, diet.

On the surface, the study published on February 15th, 2016 in Nutrition and Diabetes appears to look into the benefits that a low-carb high-fat diet has on beta cell degeneration and function in mice.

But the methods used in the study are so shocking and contrary to low-carb, Paleo, and even diabetic diets that it's hard to believe that anyone is actually taking the study seriously.

But they are.

War has been declared on the Paleo Diet, with journalists insisting that the Paleo Diet causes weight gain, all because some researchers in Australia came to an erroneous conclusion after feeding pre-diabetic mice a Paleo diet that they defined as being low-carb high-fat.

“We are told to eat zero carbs and lots of fat on the Paleo Diet,” Associated Professor Sof Andrikopoulos told the Telegraph. “Our model tried to mimic that.”

Instead of reading the diabetic journal article for themselves to see what the Australia researchers did to create that result -- and the what is so outrageous that I was literally dumbfounded when I read the journal article myself -- journalists are reacting to the conclusions presented by the article, accepting them on faith.

While I'm used to researchers using their own definition of what a low-carb diet is when designing their research studies, the design of this particular Paleo study will really blow your mind.

Characteristics of New Zealand Obese Mice

According to the paper, animal studies have previously shown that high-fat diets in animals cause fatty liver problems, which in turn affects the ability of the liver to curtail glucose production.

Mice cannot handle high-fat diets. 

In fact, many studies have shown that high-fat diets can cause beta-cell death in mice. And this holds true for both a normal level of carbohydrates as well as a high-carb diet.

The researchers decided to use New Zealand Diabetic mice (NZD mice) to explore the potential benefits of a low-carb high-fat diet for those with Type 2 Diabetes.

Not only does that not make sense, but specifically, NZD mice are created by overfeeding them. 

(This detail will be especially important when we get to the method the researchers used for their observation, so don't forget that.)

NZD mice are a strain of mice whose metabolism doesn't rev up when overfed. Instead, they store the excess energy as body fat.

In addition, these mice also have glucose intolerance issues due to beta-cell death brought on by an elevated glucose level, which causes them to become diabetic by the age of 20 weeks. 

Feeding NZD mice a high-fat diet worsens both their obesity and glucose tolerance. This is also an important point, since the tested diet was super high in fat.

Previous studies have shown that taking away all carbohydrates from these mice corrects the elevated glucose level and preserves the remaining beta cells. This means that these mice are severely insulin resistant.

Since the researchers are concerned with slowing down the degeneration of Type 2 diabetes, I found it odd that some previous research efforts was to give these mice a moderate-carb diet where 32 percent of their daily calories come from carbohydrates. 

Given their degree of insulin resistance, that high of a carbohydrate load after being zero carb caused the mice to become diabetic very quickly.

One-third of your calories would be 125 grams of carbohydrate per day for someone eating 1500 calories, a level that most low carbers wouldn't be able to tolerate, especially if they were pre-diabetic.

The average low carber can expect to be able to eat 50 to 60 carbohydrates at maintenance, without suffering carbohydrate cravings and regain, but only a few can go as high as 125.

Many low carbers can eat 60 to 120 carbs at maintenance.
Not everyone has to eat very low carb for the rest of their life.

Type 2 Diabetes occurs when insulin resistance becomes so pronounced that beta cells can't produce enough insulin to overcome the resistance.

This latest study wanted to look at the specific effects that a low-carb high-fat diet have on B-cell function. 

The hypothesis was:

If restricting carbohydrates could reduce the workload of the beta cells, insulin sensitivity might be able to recover, or at least, remarkably improve since elevated insulin levels have been known to cause beta-cell failure in mice.

That isn't what happened, though.

Not because a low-carb high-fat diet doesn't work on severe insulin resistance, but because the diet these mice were fed was not a standard low-carb high-fat diet. 

Nor was it a Paleo Diet.

How the Researchers Created Weight Gain in NZD Mice

The mice used were specifically bred and raised for the study. 

While they were given free access to plenty of drinking water, food was limited to a standard rodent maintenance diet for their first 6 weeks of life. 

At 6 weeks, the mice were divided into two groups. One group continued to receive a standard rat chow for 9 weeks, and the other group was placed on a specially designed rat chow that was supposed to imitate a Paleo Diet.

Animal feed is measured in energy density, rather than calories because a calorie is too small. As a reference, 1,000,000 calories equals 1 Mcal, and 1 Mcal equals 4.185 MJ. Keep that in mind as you look at what they did.

For the control group, the mice received chow that contained 13.5 MJ kg -1 digestible energy units, while those being fed a low-carb diet received a whopping 24 MJ kg -1 digestible energy units. 

Since NZD Mice get fat when overfed, this flawed design could not have been an accident. The low-carb mice were deliberately overfed and most of that overfeeding came from fat.

But that's only part of the problem with this study.

In addition to overfeeding the low-carb high-fat mice, the researchers fed them LCHF rat chow that was 6 percent carbohydrate and 81 percent fat. Not bad at first glance, as that imitates the macros of many doing a Nutritional Ketosis program, but take a closer look at what those carbohydrates came from:

“The carbohydrate content of the LCHFD was exclusively derived from simple sugar (sucrose: 106 g kg -1).”

THEY FED THE MICE TABLE SUGAR!

In comparison, the standard diet that the other group of mice received was 70 percent carbohydrate, which consisted of 50 percent starch and only 2 percent simple sugars, which came from monosaccharides and disaccharides.

Monosaccharides can be either straight:

• glucose
• galactose
• or fructose

Disaccharides can be either:

• maltose
• lactose
• or sucrose

So not only did the low-carb high-fat mice get double the calories, they also got fed pure table sugar, where the mice on a standard diet was fed 50 percent starches and very little table sugar, if any.

Since sugar is not eaten on a low-carb diet, and definitely not Paleo, this research study was a total farce. They gave the mice exactly what they needed to gain weight and pack on additional fat cells.

But it doesn't stop there.

The low-carb high-fat mice were also fed smaller amounts of protein in addition to the super-high calories and table sugar.

Where the standard rat chow contained 20 percent of its calories from protein, the amount of protein recommended by Dr. Phinney, the low-carb diet only contained 13 percent. 

Protein is an essential nutrient. 

It is needed to repair damaged body structures, such as beta cells. Since standard rat chow contains 20 percent protein, it's safe to assume that is the proportion of protein calories that rats need to maintain adequate body function and avoid starvation.

The Natural Sugars in Vegetables

The lower protein content in the LCHF mice gave the researchers room to raise the fat content of their diet to levels well above the amount of dietary fats that a standard low-carb diet or Paleo Diet contains. 

While the diet fed to these pre-diabetic mice appeared to fit within the macros that many doing Nutritional Ketosis have set up, including the lower protein consumption, it wasn't even a maintenance Nutritional Ketosis program due to the low protein and carbohydrate coming from table sugar.

Table sugar is 50 percent glucose and 50 percent fructose.
Vegetables are mostly glucose. 

On a real low-carb diet, most of the carbohydrates consumed come from vegetables, and the natural sugar most common in vegetables is glucose. While root vegetables do contain some sucrose in its natural form, low-carb diets do not recommend the consumption of sugar beets. 

Peas and carrots are added much later in the program, once the body has adjusted to burning fatty acids for fuel. Sweet potatoes are generally kept for maintenance.

Final Thoughts

At the beginning of the study, the body weight of the two groups of mice were exactly the same since they all were eating a standard rodent diet for their first 6 weeks of life. 

Difference in weight didn't begin to emerge until the low-carb mice had been overfed with fat for three weeks. By five weeks, the weight gain had become statistically significant.

Why the researchers expected mice to not gain weight eating a high-calorie, high-fat diet is beyond my understanding since the strain of mice they used can't tolerate overfeeding, especially high-fat diets.

But the really startling fact was that these researchers claimed that the weight gain seen in the low-carb high-fat mice didn't come from overfeeding.

If not:

Why did they site facts at the beginning of the paper that showed this is how pre-diabetes is created in this type of mouse?

I'm also having trouble understanding why they stopped the observation a few weeks short of when the average NZD mouse goes into full diabetes.

Certainly, watching to see if the mice were going to become diabetic or not on the low-carb high-fat diet they designed would have been extremely valuable information to know about LCHF diets.

Just because the mice got fat, that didn't mean they would also become diabetic.

Unfortunately, the best that can be said for this study is that it proves beyond a reasonable doubt that NZD Mice need a diet that contains little or no table sugar.

Other than that, the conclusion came to by the authors of the study, that:

“An LCHFD is unlikely to be of benefit for preventing the decline in B-cell function associated with the progression of hyperglycemia in type 2 diabetes”

is nothing more than pure imagination.

You can't give a diabetic 6 percent of their calories in pure table sugar, rather than vegetables, and then expect the disease not to continue progressing or even reverse itself. 

That's pretty outrageous. Don't you think?

Reference:

Nutrition & Diabetes, BJ Lamont, MF Waters, and S Andrikopoulos, February 15, 2016, "A low-carbohydrate high-fat diet increases weight gain and does not improve glucose tolerance, insulin secretion or B-cell mass in NZO mice."