Paleo Detractors Half-Baked Criticisms

More and more high-profile individuals are achieving measurable results on The Paleo Diet. These public triumphs threaten the antiquated low fat, high carbohydrate diets still officially endorsed by the government and prominent medical institutions. Accordingly, defenders of the low-fat doctrine are increasingly lashing out against the Paleo movement.

Just last month, The Wall Street Journal publicized NBA superstar Lebron James’ Paleo success, encapsulated by a viral photo posted to his Instagram account.¹ This prompted NBC’s The Today Show to publish an article by Registered Dietitian Elisa Zied, in which Zied asserts, "There’s little science supporting the weight loss or health benefits of a Paleo diet."²

According to Zied, the Paleo Diet “falls short on calcium and vitamin D,” and includes proportionally too much protein and fat and not enough carbohydrates. Paleo detractors say surprising things, but Zied’s comments are particularly fantastic. Let’s start with her vitamin D claim.

Vitamin D

Many are of the opinion the Paleo Diet is vitamin D deficient with the exclusion of milk, which is typically fortified with vitamin D. This would imply that non-Paleo Diets are vitamin D adequate only due to supplementation. After all, fortified milk is simply a food combined with a supplement. It would therefore be strange to call the Paleo diet vitamin D deficient when vitamin D supplements, if necessary, could always be added to the Paleo Diet.

According to the Institute of Medicine (IOM), we should be consuming 600 IU/day of vitamin D with an upper limit of 4,000 IU/day.³ Excluding fortified foods, the foods richest in vitamin D are fish and seafood, which, of course, are Paleo compliant. Just 100g of herring, for example has over 1,600 IU. Mackerel, sardines, salmon, trout, halibut, and shrimp are also particularly good sources.

Calcium

Others speculate the Paleo Diet also “fall short on calcium” because it excludes dairy. The IOM recommends 1,000 mg/day of calcium for adults with an upper limit of 2,500 mg. The foods highest in calcium are Paleo foods, including leafy green vegetables, herbs, and clams. A standard Paleo Diet, including plenty of leafy greens and seafood provides plenty of calcium.

Fat to Protein Ratio

In her article, Zied references a recent review of 19 studies published in PLoS, which concluded that overweight and obese people lose similar amounts of weight whether on low-carb or low-fat diets.⁴ But if you look at those 19 studies, one by one, the low-carb, Paleo Diets are clearly favorable. 9 of the 19 studies showed cardiovascular disease risk factors decreased on low-carb diets compared to low-fat diets. 8 of the studies suggest that low-carb and low-fat diets yield similar results, and only 2 studies, both published by the same author, suggest low-fat diets are better. Furthermore, the PLoS study did not include at least 10 additional randomized controlled trials (RCTs) comparing low-carb and low-fat diets, all of which show low-carb diets to be superior for weight loss and/or the prevention of metabolic syndrome and cardiovascular disease.^{5, 6, 7, 8, 9, 10, 11, 12, 13, 14}

The latest, recently published study, funded by the National Institutes of Health concluded, "The low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet. Restricting carbohydrate may be an option for persons seeking to lose weight and reduce cardiovascular risk factors."¹⁵ Zied claims little scientific evidence supports the Paleo Diet, but in fact over 60 published studies support core aspects of the diet.

Criticisms to the Paleo Diet are consistently unscientific, which suggests these challenges are perhaps motivated by an interest in protecting the obsolete low-fat model of nutrition.