March is National Nutrition Month and to spread awareness about the importance of eating right, we hear from Chrissy Carroll, a registered dietician who talks about the pros and cons of the Paleo Diet.
The grapefruit diet, the Atkins diet, the cabbage soup diet – you’ve heard them all. But recently, a new diet has entered the scene – the Paleo diet. Also called the Stone Age diet or the Caveman diet, this meal plan suggests eating a diet closer to what our cavemen ancestors ate. It focuses on lean meat, fish, fruits, vegetables, and nuts, while completely cutting out dairy, grains, legumes, beans, processed oils, sugar, and added salt. Some versions also limit the fruit consumption to certain portions or times per day.
The diet is based on the theory that our core genetic makeup hasn’t changed since the paleolithic era, and in that era people didn’t experience as much chronic disease. And so comes the conclusion that the diet cavemen ate is best for preventing chronic disease…
There are a few issues with this theory, though. Let’s take a look…
1) The first major issue is that we don’t know exactly how our ancestors ate, so the diet is based on our assumptions. While we can find out certain indications of what was eaten based on carbon dating, carved images, etc – no one can definitively tell us what our ancestors ate on a regular basis. In all reality, their diet probably wasn’t quite as straight forward as the Paleo diet seems to indicate. Our ancestors likely moved around and ate whatever was available in the area they were living in or moving through.
Some proponents of Paleo will claim that the body doesn’t even need as much food, because our ancestors fasted many times when food wasn’t available. The counterargument is this: don’t you think if they had food readily available, they would have eaten it? It isn’t likely that they voluntarily chose to fast.
2) This diet also assumes that the human body has not adapted to be able to eat grains and dairy, and that these foods contribute to overweight/obesity, heart disease, and other health problems. However, is there really solid evidence of this? Are we writing off the last 10,000 years of agriculture as something that none of us can really tolerate? It seems a bit hard to believe. Rates of overweight and obesity have skyrocketed in the last 30 years – not 10,000. Certainly there are individuals with lactose intolerance, celiac disease, or gluten sensitivities that may have to alter intake of these food groups. But I see no definitive scientific evidence that our bodies have not “adapted” to process grains and dairy. On the contrary, it seems that many generations before us led perfectly healthy lives eating these foods.
3) The average life expectancy of a caveman was about 20 years. Now, this is of course skewed by the fact that there were lots of problems we consider minor now that did not have medical treatment back then – an infection or a broken ankle, for example. In those times, these issues could lead to death. But given that much of the population did not live older than this, it’s hard to judge if the type of diet they ate truly prevented chronic disease, simply because most did not live long enough to develop chronic disease.
4) Quick, pretend you’re a caveman and you want to get some food. What do you have to do? Go out and kill it. You want to go visit your friend? Guess you’ll have to walk a mile over there. The activity level for this generation was much higher than our current activity level. It’s a factor that we can’t tease out of the equation.
All these assumptions and questions make this dietitian a bit skeptical. Am I saying that there are no benefits to the Paleo diet? No, of course not. There certainly are some good parts of the diet. But there are some detrimental parts as well – namely a lack of certain micronutrients, like calcium, and potentially too much saturated fat. The reason many people lose weight and see improvements in their health on this diet comes from simply making healthier food choices. Individuals are cutting out refined, processed foods and choosing more produce. These changes can reduce the number of calories consumed to help aid in weight loss. Because you’re eating more natural foods, there’s less added fat and sugar that contributes to other problems like heart disease.
Is there research supporting any benefit to this diet? There are a few studies. For example, a study found that a Paleo diet improved glycemic control, BMI/weight, and cardiovascular risk factors compared to a diabetic diet among those with Type 2 diabetes.
There are several limitations to the conclusions that can be drawn, though. The study was small – there were only 13 participants. It was not blinded after initial diet selection. In addition, reading further into the study showed that the Paleo diet was lower in total calories and carbohydrate and higher in fruits and vegetables compared to the Diabetes diet (average of 1581 ± 295 in the Paleo diet compared to 1878 ± 379 in the Diabetes diet). Could some of the proposed benefits, particularly weight, come from the fact that there were significantly less calories eaten on the Paleo diet – as opposed to the composition of the diet itself? I’d be inclined to say so.
Why adhere to such a strict diet when large bodies of research are lacking – and when there is research to support the benefits of much more flexible meal plans, like a Mediterranean diet, or simply balanced meal plans that reduce processed foods? There is no scientific reason to date that someone must cut out grains, beans, and dairy products from their diet if they currently tolerate them well. Whole grains provide a healthy source of carbohydrates for energy, as well as heart-healthy and digestive-friendly fiber. Dairy products provide a major source of calcium in the Western diet, and while there are certainly additional sources of calcium outside of dairy products – if you like dairy and tolerate it, there’s no reason to eliminate it from your diet. Along the same lines, beans and other legumes are great inexpensive sources of protein and fiber.
There are also the issues of lack of variety and cost associated with the Paleo diet. With meat being one of the most expensive items in our grocery cart, eating this way can be quite pricey. And after a while of following this diet strictly, you might find yourself craving more variety. The strict nature of this diet makes it much more likely for people to give up and rebound to old habits. And of course, there’s the issue of global sustainability – it’d be impossible to support a global food supply on a Paleo type diet.
Lastly, even if you aimed to follow a strict Paleo diet, it’d be very difficult to eat the foods in the manner they existed millions of years ago. Most of the meat available today is domesticated. Fruits and vegetables are grown on farms, not picked from the wild. There isn’t much wild game running around that we’re planning to eat. Not to mention, as soon as we start taking components of one diet and figuring out ways to tweak our favorite foods, we start adding back unhealthy components. I just saw a “Paleo-friendly” chocolate cake recipe made with almond flour and coconut oil. Here’s the thing – regardless of the fact that it doesn’t have butter or real flour, chocolate cake is still chocolate cake, and I’m pretty sure cavemen weren’t whipping these up for themselves.
The bottom line: The Paleo diet certainly has some advantageous components, like focusing on natural, unprocessed choices and increasing produce consumption. But for most people, there’s no scientific reason to cut out broad categories of foods like whole grains, legumes, and dairy. If you want to lose weight and improve your health, eat a balanced diet including lean protein, healthy fats, and carbohydrates while cutting out most processed foods.
Chrissy Carroll is a Registered Dietitian and ACSM Certified Personal Trainer. She earned her Masters of Public Health in Nutrition from UMass Amherst and her Bachelors of Nutritional Science from Boston University. A marathoner and triathlete, Chrissy has a passion for fitness and healthy eating that she loves sharing with her clients. She owns Inspired Wellness Solutions, LLC, a nutrition and fitness counseling practice based out of Mansfield, Massachusetts.