Tag Archives: dietary guidelines

Eliminate Food Groups | The Paleo Diet
Do you believe that “our modern lifestyles, including nutrition, are the cause of current health problems?” If so, you could be susceptible to “fad diets,” according to the United Dairy Industry of Michigan (UDIM). Last week, the organization’s Technical Advisor for Nutrition, Lois McBean, wrote that those who follow the Paleo diet “are likely setting themselves up for nutritional deficiencies by eliminating entire food groups such as dairy, grains, and legumes.”1

McBean went on to observe, “Such restrictive diets are not consistent with current dietary recommendations including USDA’s MyPlate or the 2010 Dietary Guidelines for Americans.” It’s interesting that she invokes the 2010 Guidelines, considering that earlier this year, the Dietary Guidelines Advisory Committee (DGAC) acknowledged that the 2010 and previous Guidelines contain a glaring error.

In the DGAC’s own words, “Previously, the Dietary Guidelines for Americans recommended that cholesterol intake be limited to no more than 300 mg/day. The 2015 DGAC will not bring forward this recommendation because available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol.”2

The 2010 and previous Guidelines were wrong about cholesterol, a mistake that likely persuaded millions of people to avoid eggs, shrimp, and other healthy, cholesterol-rich foods. Is it conceivable that the Guidelines could also be wrong about dairy, cereals, and legumes? We’ll address this question, but first let’s examine the idea of “eliminating entire food groups.”

Eliminating Entire Food Groups

Paleo critics like McBean seem to think the USDA’s MyPlate is inclusive of all food groups, but surprisingly, it excludes the most nutrient dense food group of them all – organ meat. The Paleo diet, on the other hand, excludes dairy, cereals, and legumes because, despite the nutrients they contain, they also contain antinutrients and promote various adverse health effects. But what possible reason could the USDA and Paleo critics have for excluding organ meat?

In the US, organ meat fell out of favor decades ago, but in most other countries it’s embraced and recognized for its remarkably high nutrient levels. Those who worry about nutrient deficiencies should be questioning the exclusion of organ meat (an entire food group) before criticizing those who, for valid reasons, exclude dairy, cereals, and legumes.

Nutrient Deficiencies

McBean lauds dairy foods as “important sources of multiple essential nutrients, including calcium, vitamin D, and potassium,” while implying that the Paleo diet falls short on these nutrients. This is an interesting comment for three reasons:

1. Dairy is not a rich source of potassium

The charts below show potassium, vitamin D, and calcium levels for 100g portions of common foods. Paleo foods are highlighted in orange, non-Paleo foods in purple. All values are for uncooked foods; note that 100g doesn’t necessarily represent a serving size. For example, beans are richest in potassium, but once cooked, potassium is significantly diluted because the beans absorb so much water. As shown, Paleo foods, including vegetables, seeds, nuts, mushrooms, fruit, fish, and meat, provide plenty of potassium.

How much potassium is enough? The National Academy of Sciences (NAS) sets the Daily Recommended Intake (DRI) for all nutrients. For potassium, however, instead of a DRI they set an Adequate Intake (AI) level of 4.7g per day. The NAS notes, “dietary intake of potassium by all groups in the United States and Canada is considerably lower than the AI.”3 With so many potassium-rich foods to choose from (note: the chart is not comprehensive), the Paleo diet emerges as the solution for potassium deficiency, not the cause.

Potassium | The Paleo Diet

2. Most of dairy’s vitamin D comes through fortification

Vitamin D | The Paleo Diet[/one_half]

Dairy fat does contain a small amount of natural vitamin D, but non-fat and low-fat dairy have almost none. As shown in the chart, the foods highest in vitamin D are Paleo foods, namely fish, shrimp, eggs, and to a lesser degree organ meat and mushrooms. Even fortified dairy doesn’t provide spectacular amounts.

Furthermore, if you want to go the fortification route, you’re much better off with vitamin D supplements, in which case you could avoid the negative effects of dairy. Note that the DRI for vitamin D is 600 IU/day.

3. Dairy is indeed high in calcium, but the calcium story is nuanced

As Dr. Cordain has explained extensively, net calcium balance (NCB) is far more important than calcium intake. NCB equals calcium intake minus calcium excretion. Calcium excretion is largely a function of acid/alkaline balance. For diets with net acid loads, the body’s calcium salts, which are stored within the bones, are excreted to maintain balance. For diets with net alkaline loads, endogenous calcium stores are unaffected.

Calcium | The Paleo DietThe only alkalizing foods are vegetables and fruit. The Paleo diet is more alkaline than MyPlate because of its emphasis on vegetables and its exclusion of dairy, cereals, and legumes. As shown in the chart, calcium in the Paleo diet comes from seeds, nuts, bones, vegetables, and from the fact that proportionally less calcium is excreted, due to the diet’s alkalinity. Note that the DRI for calcium is 1,000 mg/day.

Despite its calcium levels, dairy causes more problems than it solves. According to the US National Library of Medicine, an estimated 65% of the global population is lactose intolerant.4 Additionally, drinking 3 cups of milk per day, as McBean and the UDIM recommend, is associated with an increased risk of bone fractures as well as increased overall mortality, according to a cohort study published by the British Medical Journal.5 This study was observational, so it cannot prove causation, but it underscores the net acid load problem and other problems associated with dairy.

Far from promoting nutrient deficiencies, a careful examination of the evidence shows the Paleo diet reverses nutrient deficiencies caused by junk food and other imbalanced diets. This is accomplished by eliminating problematic food groups, including dairy, cereals, and legumes, while embracing the healthiest food groups, including meat, fish, organ meat, vegetables, nuts/seeds, and fruit.

References

1. McBean, L. (November 4, 2015). Fad Diets: Be Careful What You Wish For. United Dairy Industry of Michigan.

2. Dietary Guidelines Advisory Committee. (February 2015). Scientific Report of the 2105 Dietary Guidelines Advisory Committee. USDA and Department of Health and Human Services.

3. National Academy of Sciences. Institute of Medicine. Food and Nutrition Board. (2004). Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate.

4. Genetics Home Reference. (May 2010). “Lactose Intolerance.” U.S. National Library of Medicine.

5. Michaëlsson, K., et al. (October 2014). Milk intake and risk of mortality and fractures in women and men: cohort studies. The British Medical Journal, 349.

6. Schmid, A and Walther, B. (July 2013). Natural Vitamin D Content in Animal Products. Advances in Nutrition, 4(453-462).

The End of the Low-Fat Era? | The Paleo Diet

The year was 1977. The US Senate Select Committee on Nutrition and Human Needs, led by Senator George McGovern, issued the first Dietary Goals for Americans, thereby marking the beginning of the low-fat era of dietary nutrition, arguably the most misguided period of government-led nutrition ever. After 38 years, however, the low-fat era might officially end later this year.

The Dietary Goals evolved into the Department of Health and Human Services’ (HHS) and Department of Agriculture’s (USDA) Dietary Guidelines for Americans, later represented as the Food Pyramid and, currently, as MyPlate. The Guidelines’ dominant theme has been that calories consumed should equal calories expended. And since fat has 9 calories per gram, compared to only 4 for both carbohydrates and protein, fat became typecast as the “bad guy” nutrient.

Furthermore, since saturated fat and dietary cholesterol have been thought to promote cardiovascular disease, the Guidelines have recommended restricting fat to less than 30% (revised to 35% in 2005) of total calories. Consequently, carbohydrates, particularly refined carbohydrates and added sugars, came to replace healthy fats in Americans’ diets.

USDA and HHS update the Guidelines once every five years and the next revision is forthcoming later this year. Historically, the Guidelines echo the Dietary Guidelines Advisory Committee (DGAC) report, written by appointed scientists who systematically review the scientific literature on nutrition. The current DGAC report, published earlier this year, features two monumental deviations from the current Guidelines.

First, as we previously reported, the DGAC no longer considers dietary cholesterol to be a “nutrient of concern.”1 Previously, they recommended limiting cholesterol to 300 mg/day, but now acknowledge, “available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol.”

Second, the DGAC recommends removing upper limits on total fat consumption with respect to total calories. “In low fat diets,” they write, “fats are often replaced with refined carbohydrates and this is of particular concern because such diets are generally associated with dyslipidemia.”2 Reducing total fat (replacing total fat with overall carbohydrates), they conclude, “does not lower cardiovascular disease risk.”

So what does all this mean? If USDA and HHS follow the DGAC’s recommendations, the low-fat era will finally end and, going forward, Americans will have more scientifically accurate information about fat and will likely embrace healthful, fatty foods more readily.

CALLING ALL NUTRITION ADVOCATES

The DGAC recommendations are clear, but in making their final decision, the USDA and HHS also consider comments from the public, academics, advocacy groups, and industry. As such, two prominent scientists, Dr. David Ludwig and Dr. Dariush Mozaffarian, recently penned an article for the Journal of the American Medical Association in which they strongly endorsed lifting the total fat limits.3

Their article follows-up on a similar article they co-authored in 2010 about the previous Dietary Guidelines update. In their 2010 article, they recommended moving away from a nutrient-metrics approach, whereby specific nutrient targets are defined, and toward an approach emphasizing specific, healthy foods. They noted that the proportion of total energy from fat “appears largely unrelated to risk of cardiovascular disease, cancer, diabetes, or obesity” and that saturated fat “has little relation to heart disease within most prevailing dietary patterns.”4

We recently caught up with Dr. Mozaffarian to ask him about this extremely important story.

Q: What are your impressions about the progress made since your 2010 article with Dr. Ludwig? Are we moving in the right direction?

A: The 2015 DGAC report has made great strides in the right direction, with its major new focus on healthful, food-based, diet patterns. Now we must wait to see what the USDA and HHS do with this information in the final Guidelines—boldly move toward this modern evidence, or sit back and return to old conventions.

Assuming the USDA drops its limits on total fat consumption, how impactful do you think this could be?

This could have tremendous positive impact, especially if mirrored in other national policies e.g. food labeling, school lunch, feeding programs, and so on. Consumers and companies would be unshackled to allow focus on increasing healthy foods, including those higher in fat, and on reducing refined grains and sugars.

Would you care to comment on the Paleo diet from a nutritional perspective?

The main benefits of Paleo are recognizing the harms of refined grains, starches, and sugars, which dominate the food supply; and the (potential) focus on fruits, vegetables, nuts, and fish. But, if ‘Paleo’ leads one to high-meat diets, few benefits will be gained.

Dr. Mozaffarian makes a valid point. One of the largest misconceptions surrounding Paleo diets and lifestyles is that it promotes high-meat consumption without balance from other food groups. Dr. Cordain among the many other thought leaders in the scientific and lay communities continue to debunk this misconception. A real Paleo diet is a high-vegetable diet with moderate amounts of animal protein, including lean meat and fish high in omega-3, plus animal and vegetable sources of fat.

In our interview with Dr. Mozaffarian, he also noted that some vegetable oils “are extremely healthy, but are shunned by many Paleo aficionados.” While we respectfully disagree about the health impact of high-omega-6 vegetable oils, we strongly agree that proportional upper limits on total fat must be removed from the US Dietary Guidelines.

For nearly four decades, the US government has promoted high-carbohydrate, low-fat diets. Incidentally, a recent systematic review of the randomized controlled trials available to McGovern’s Committee back in 1977 determined there was no scientific basis for their restrictions on fat.[5] In other words, the low-fat era never should have happened. And with the 2015 Dietary Guidelines update, it should finally end.

 

REFERENCES

[1] Dietary Guidelines Advisory Committee. (February 2015). Scientific Report of the 2015 Dietary Guidelines Advisory Committee.

[2] Ibid, Dietary Guidelines Advisory Committee.

[3] Dariush Mozaffarian and David S. Ludwig. (June 2015). The 2015 US Dietary Guidelines: Lifting the Ban on Total Dietary Fat. Journal of the American Medical Association, 313(24).

[4] Dariush Mozaffarian and David S. Ludwig. (August 2010). Dietary Guidelines in the 21st Century—a Time for Food. Journal of the American Medical Association, 304(6).

[5] Z Harcombe, JS Baker, SM Cooper, B Davies, N Sculthorpe, JJ DiNicolantonio and F Grace. (February 2015). Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis. Open Heart, 2.

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