Low-carb diets like the paleo, Atkins, and ketogenic programs are all the rage. How did they come to be so popular? And are they sustainable in the long run?

 

This is Part I of III in my series on low carb diets and fiber. In this entry I explain the history behind the low-carb eating movement and explore some common pitfalls of this diet. In Part II I’ll explain the importance of eating enough fiber, and in Part III I’ll offer suggestions and recipes to help you increase your fiber intake while following a low-carb/healthy eating regimen.

 

A Brief History of Bread & Butter

In 1992 the United States Department of Agriculture (USDA) issued updated guidelines for healthy eating. The Food Pyramid, as their creation was called, encouraged Americans to make carbohydrate-rich foods like breads, cereals, rice, and pasta dietary cornerstones – with a suggested intake of 6 to 11 servings of these foods per day,[1] and no distinction made between refined carbohydrates (like pasta) and whole grains (like buckwheat). By then Americans had already heard the warnings of doctors like Ancel Keys, who claimed that foods like butter and bacon “clogged arteries” and caused heart disease (a claim we now know is patently false).

After decades of eating diets high in carbohydrates and low in fats, however, Americans have not enjoyed better health, but rather a sharp and terrifyingly steep increase in numerous preventable diseases.[2] In fact, the consumption of refined carbohydrates has since been correlated with increased risk of obesity[3] (with Americans now being among the fattest and unhealthiest people in the world),[4] stroke,[5] diabetes,[6] depression,[7] and even neurocognitive deficits (problems with focus, memory, and task performance).[8]

Recent studies have demonstrated that as compared to low fat diets, diets that restrict carbohydrate intake are associated with healthy weight loss (with the reduction of fat mass, as opposed to muscle), the reduction of “bad” cholesterol levels, and increases in “good” cholesterol counts.[10] Of the over 3,300 adults assessed in one such study, those whose blood levels were higher in byproducts derived from full-fat products like butter were shown to be almost half as likely to develop diabetes as those with lower levels.[9] In other words: the advice we heard in the 90’s – that we should avoid fat and eat mostly carbohydrates – was entirely wrong.

 

Enter the Low-Carb Movement

As the old saying goes, “You don’t need a weatherman to know which way the wind blows.” Doctors, nutritionists, and everyday people can clearly see that the high carb/low fat diets are making us fat, sick, and depressed. This realization has ushered in an entire food revolution – enter Dr. Robert Coleman Atkins, the paleo movement, the ketogenic diet, the Whole30, the slow-carb fad, and other plans that emphasize vegetables, naturally sourced fats, and animal proteins – and avoid carbohydrates (or “carbs”) like the plague.

By definition, low-carb diets entail avoiding processed carbohydrates such as most breads, pastas, crackers, and pastries – pretty much anything made from a refined grain-based flour, such as wheat flour. The refining process not only increases the glycemic index of these grains (the degree to which they increase blood sugar), but also reduces their fiber content. Refining also often removes the vitamins, minerals, and other nutrients originally found in the whole grain. Refined carbohydrates clearly have little to no nutritional value and come with significant health risks, and are thus excluded from the new wave diets.

But eating plans like the ketogenic (aka “keto”) diet are so carbo-phobic that they also eliminate unrefined whole grains (like wild rice, millet, and oats) as well as fiber-dense legumes (like navy beans and peas). Is that really necessary? Are natural, unrefined carbohydrates really making us fat, sick, and miserable?

Maybe not.

Now, don’t get me wrong: I often prescribe low-carb programs such as these. In fact, I have helped numerous individuals overcome conditions like obesity, fatigue, heart disease, diabetes, and even depression largely through dietary changes. But after a (rather strict) initial treatment period, there is often a re-integration phase to ensure that my patients’ dietary habits are not only nutrient-dense, but also sustainable. Although refined carbohydrates (breads, cakes, bagels, and the like) are never “invited” back into the diet, other, natural, unrefined carbohydrates like lentils, black beans, and teff are typically reintroduced without any backsliding or loss of benefit to the patient. (That being said, I have never seen a person with diabetes maintain reasonable blood glucose levels after eating white or brown rice.)

We might be throwing out the baby with the bathwater when we say all carbs are bad. While this strict elimination is indeed helpful for some when jumpstarting a new health plan, it might not be necessary – or even healthy – for most people to be this vehemently anti-carb in the long haul.

 

Some Risks of Low-Carb Eating

Unlike many other diets (such as the vegan diet, which is lacking in heme iron, low in vitamin B12, and lacking in protein), it is entirely possible to get all of the nutrients one needs on a low-carb eating plan. That being said, low-carbohydrate diets are not entirely foolproof.

In our busy, fast-paced society, it becomes all too easy for all of us – regardless of our food “religion” – to eat pre-packaged, grab-and-go fare instead of balanced meals. Before the market caught up with the paleo eating trend, going low-carb meant menu planning and packing your own lunch. Nowadays it entails quickly inhaling some gluten free jerky between meetings. As wonderful as protein is – really, the amino acids found in animal protein are some of my favorite allies in helping patients battle fatigue and mood disorders – we can’t live on animals alone. (And we’ll certainly never have healthy bowel movements if we try!)

Curiously, the grab-and-go modern-day caveman often doesn’t eat enough vegetables. There’s bacon and eggs (or bulletproof coffee) for breakfast, an almond-flour muffin with nut butter at lunch, some dark chocolate mid-afternoon for a pick-me-up, and steak at dinner – but where are the veggies!? It’s surprising the lengths humans will (unknowingly) go to in order to avoid eating vegetables. Even those eating the so-called plant-based diet are often guilty of not eating enough vegetables! That’s why I suggest that just about everyone, no matter what diet they’re following, aims for at least half of their plate at every meal to be comprised of vegetables. (Potatoes, corn, and peas don’t count.)

While the average Westerner spends way too much time parked on their tuchus (we even defecate sitting down!), people with active lifestyles may actually need the quick-burning fuel available in carbohydrate-rich foods. Endurance athletes, for example, typically need to consume carbohydrates to properly fuel their workouts. That’s not a free ride to eating cookies and English muffins with marshmellow Fluff, however. “Healthy carbs” like sweet potatoes, black-eyed peas, and quinoa are all good choices to help athletes avoid feeling sluggish and weak. (Note: going for a 30-minute run every morning does not typically put one in the endurance athlete/carb-needing camp.)

The other major concern I with low-carb diets – and the topic of my next post – has to do with fiber. It is very easy to skimp on fiber intake while eating a low-carb diet because meat and dairy products contain zero fiber. Zilch. Zip. Fruits and vegetables contain some, but not nearly enough to meet the dietary demands of most people (which I’ll outline in greater detail in the next post).

Fiber is essential for our health, and not eating enough of this important constituent can have serious consequences in both the short and long term.

 

So, is it possible to be a healthy caveperson? Absolutely!

Let’s now take a closer look at why fiber is so important.

In Part III of this series I’ll offer some tasty and easy ideas on paleo-friendly ways to increase your intake of this important nutrient. (And if some navy beans and amaranth slip into your diet? You’ll probably be just fine too.)

 

 

References

[1] Welsh S, Davis C, Shaw A. Development of the Food Guide Pyramid. Nutrition Today. November/December 1992:12-23.

[2] Aune D, Norat T, Romundstad P, Vatten LJ. Whole grain and refined grain consumption and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies. Eur J Epidemiol. 2013 Nov;28(11):845-58. doi: 10.1007/s10654-013-9852-5. PMID: 24158434.

[3] Spadaro PA, Naug HL, DU Toit EF, Donner D, Colson NJ. A refined high carbohydrate diet is associated with changes in the serotonin pathway and visceral obesity. Genet Res (Camb). 2015 Dec 28;97:e23. doi: 10.1017/S0016672315000233. PMID: 26707058.

[4] Obesity Update 2017. OECD. Available from: https://www.oecd.org/els/health-systems/Obesity-Update-2017.pdf

[5] Yu D, Zhang X, Shu XO, Cai H, Li H, Ding D, Hong Z, Xiang YB, Gao YT, Zheng W, Yang G. Dietary glycemic index, glycemic load, and refined carbohydrates are associated with risk of stroke: a prospective cohort study in urban Chinese women. Am J Clin Nutr. 2016 Nov;104(5):1345-1351. PMID: 27733400.

[6] Gross LS, Li L, Ford ES, Liu S. Increased consumption of refined carbohydrates and the epidemic of type 2 diabetes in the United States: an ecologic assessment. Am J Clin Nutr. 2004 May;79(5):774-9. DOI: 10.1093/ajcn/79.5.774. PMID: 15113714.

[7] Gangwisch JE, Hale L, Garcia L, Malaspina D, Opler MG, Payne ME, Rossom RC, Lane D. High glycemic index diet as a risk factor for depression: analyses from the Women’s Health Initiative. Am J Clin Nutr. 2015 Aug;102(2):454-63. doi: 10.3945/ajcn.114.103846. PMID: 26109579.

[8] Hawkins MAW, Keirns NG, Helms Z. Carbohydrates and cognitive function. Curr Opin Clin Nutr Metab Care. 2018 Jul;21(4):302-307. doi: 10.1097/MCO.0000000000000471. PMID: 29851417.

[9] Yakoob MY, Shi P, Willett WC, Rexrode KM, Campos H, Orav EJ, Hu FB, Mozaffarian D. Circulating Biomarkers of Dairy Fat and Risk of Incident Diabetes Mellitus Among Men and Women in the United States in Two Large Prospective Cohorts. Circulation. 2016 Apr 26;133(17):1645-54. doi: 10.1161/CIRCULATIONAHA.115.018410. PMID: 27006479.

[10] Bazzano LA, Hu T, Reynolds K, Yao L, Bunol C, Liu Y, Chen CS, Klag MJ, Whelton PK, He J. Effects of low-carbohydrate and low-fat diets: a randomized trial. Ann Intern Med. 2014 Sep 2;161(5):309-18. doi: 10.7326/M14-0180. PMID: 25178568.

Image courtesy of Edgar Castrejon for Unsplash.