Last week, former president Bill Clinton announced that he had been following a low-fat, plant-based diet and stated that this near-veganism helped reverse his cardiovascular disease. Yes, the same Bill Clinton parodied on Saturday Night Live as a politician who grabbed fast food hamburgers right out of the hands of his supporters and proceeded to devour them in record-setting time. The benefits vs. risks of a vegan lifestyle have since been debated by the low carb/Paleo community in the blogosphere and on Twitter.
Is a vegan diet healthy? Is it more or less effective than carbohydrate restriction for management of obesity, heart disease, and diabetes? As a dietitian who prides herself on thinking outside the box, I believe all types of diets can be embraced as long as they are healthy and meet an individual's specific nutrition needs. However, there are several nutrients that are often lacking in a strict vegan diet.
There are studies suggesting that both vegan and low-carbohydrate diets can improve markers for cardiac risk. Although many regard a vegan diet as healthier because it contains less saturated fat, one of my previous posts on high-fat, low-carb diets argues that this way of eating can also promote cardiac health.
Replacing meat, fish, dairy, and eggs with large amounts of plant proteins like rice, corn, wheat, beans and other legumes results in a large carbohydrate load, which increases insulin requirements to maintain appropriate blood glucose levels. Given that many overweight and obese people have insulin resistance, impaired glucose tolerance, or diabetes, a vegan diet would likely worsen their glycemic control and further impair insulin sensitivity. People with Type 1 diabetes would need more insulin to cover the high amount of carbohydrates, and because smaller dosages of insulin are more predictable than larger ones, their blood sugar levels would tend to be more erratic.
Which is better to achieve and maintain weight loss, a vegan or low-carbohydrate diet? I've met and heard about many people who have had success with either plan. I hate to generalize, but most vegans I know are quite thin. Are they healthy? I'm not sure. It's hard for me to believe veganism can lead to optimal health given its nutritional limitations and the fact that we evolved on an omnivorous diet that was quite high in meat and fish. That being said, I believe everyone has a right to choose whatever diet they wish, and there are certainly healthier ways of practicing veganism, i.e., including lots of nuts, avocados, and other fats; consuming large amounts of vegetables, and supplementing aggressively with key nutrients, including amino acids. For my part, I will continue to promote a low carbohydrate lifestyle for reducing weight, improving blood sugar levels and cardiac health, and providing other important health benefits. Among my dietitian friends and colleagues, only a handful support my efforts, and one just happens to be a strict vegetarian/near vegan. Vive la Différence!
When I want to prepare intricate appetizers or desserts, I have plenty of options: low-carbohydrate cookbooks, websites, and a few recipes given to me by friends. But there are times when I just want to throw something together quickly and with minimal effort, particularly after a busy workday. Below are 10 fast and healthy treats (some savory, some sweet) that allow me to indulge while remaining within low-carb guidelines; each is well below 10 net grams of carbs per serving. I think they're all delicious and would love to get your feedback as well. Enjoy!
Last weekend, the first Ancestral Health Symposium was held at the University of California, Los Angeles. Unfortunately, by the time I learned about it a few weeks earlier, the event had already sold out. Really a shame, considering it would have only taken me about 30 minutes to drive there. I am a fairly new low-carb devotee and am still learning about Paleo nutrition, a major focus at the symposium. Also known as the Caveman Diet or Primal Diet, this way of eating based on the diet of our ancestors is an extremely popular version of low-carbing. Plans are already under way for next year's AHS. It's my understanding that it will also be held at UCLA, so at this point I'm planning to go.
The event featured many speakers well known and respected in the Paleo community, including Robb Wolf, Andreas Eenfeldt, Chris Masterjohn, and several others. If you have the time, I encourage you to check out the presenters ' blogs and the videotaped presentations from the event. Very interesting and inspiring!
Briefly, my take on the Paleo movement is that we can clearly improve our health by eating minimally processed foods, avoiding grains and other high-carbohydrate foods introduced only in the past few hundred years, and consuming liberal amounts of fat from both animal and plant sources. However, I believe there is no “best” way to eat; a person's diet should be tailored to the individual depending on his or her unique physiological makeup, food preferences, and carbohydrate tolerance. We also cannot say with 100% certainty exactly what those living in the Paleolithic era ate. Rachel Flowers of Altern-e-fit had similar sentiments in her blog post today.
I believe I can learn a lot from the leaders of the Paleo community, many of whom have backgrounds in medicine, science, and anthropology. While I respect and applaud those who follow any form of the Paleo diet, at this point it's a bit too restrictive for me. Aside from butter and cream, dairy foods are not allowed on the plan. Personally, I love Greek yogurt, cottage cheese, and many other types of cheese. These are great low-carb options that provide variety, as well as calcium, potassium, and other micronutrients. I see no need to give up dairy at this time. I also use sugar substitutes, primarily stevia, which are discouraged among true Paleo/Primal eaters. Today's sugar substitutes allow me to create low-carb desserts that taste remarkably like the real thing. So while I probably eat fairly close to the way our ancestors did in terms of macronutrient composition, I wouldn't call my way of eating a Paleo diet. A Primal diet? Perhaps, but that doesn't completely describe it either. I'd say I'm following a low-carb, higher-fat, moderate-protein diet that contains few processed foods and allows me to keep my blood sugar under control while feeling extremely satisfied. Kind of a mouthful, but accurate!
One of the questions that comes up repeatedly for me -- from colleagues as well as friends -- is whether following a low-carbohydrate, high-fat diet could be detrimental to heart health. A chief concern is that eating foods high in fat, particularly saturated fat, will raise cholesterol levels, thereby increasing the risk of atherosclerotic heart disease. It doesn't really surprise me; after all, for more than 30 year fats have been considered the primary food we should all be cutting back on if we want to avoid coronary artery disease. The USDA's Dietary Guidelines for Americans and My Plate promote whole grains, nonfat milk, fruits, and other foods that are high in carbohydrates and low in fat as a way of decreasing cardiac risk. On the other hand, there is a large body of research showing that lowering carb intake and increasing consumption of fat (both saturated and unsaturated) can result in favorable changes in serum lipids.
Below are a some of the cardioprotective benefits of low-carbohydrate, moderate-protein, high-fat diets:
1. Significant decrease in serum triglycerides. Carbohydrates are a potent stimulator of hepatic triglyceride synthesis and plasma concentration, particularly in the presence of insulin resistance. Lowering carbohydrate intake can reduce triglyceride levels, resulting in lower cardiac risk.
2. Increase in HDL cholesterol. Higher fat intake is positively correlated with improvements in HDL levels, and high HDL cholesterol is considered cardioprotective.
3. Improvement in LDL particle size, glycation, and oxidation. While triglycerides levels almost invariably decline with carbohydrate restriction, LDL cholesterol response appears to be more individualized. LDL has been classified as the "bad" cholesterol for years, and elevated levels are often seen as increasing one's risk of arterial plaque formation and heart disease. However, simply looking at the amount of serum LDL itself gives us very little information about cardiac risk. It is primarily when LDL is oxidized and its particle size small that this lipoprotein becomes most problematic. Restricting carbohydrate intake has been shown to reduce glycation and subsequent oxidation of LDL. A lower-carb, higher-fat diet tends to produce an increase in LDL particle size (known as Pattern A), whereas an abundance of dietary carbohydrate typically results in smaller, denser particles (Pattern B) that increase the likelihood of atherosclerosis.
I also often hear, "If people don't eat whole grains and legumes, how can they consume adequate fiber?" Fiber, particularly the soluble type, has many health benefits. A low-carb diet can easily supply sufficient fiber if it contains plenty of nonstarchy vegetables, nuts and nut butters, seeds, berries, and avocados. Technically a fruit, an average avocado contains about 12 grams of fiber, as well as 16 grams of monounsaturated fat.
As a registered dietitian, I can't endorse a low-carbohydrate diet consisting of 6 eggs fried in butter with 4 slices of bacon for breakfast, 3 hamburger patties for lunch, and a 20-oz steak with a tiny green salad for dinner. While certainly nearly carb-free, it's missing a lot of beneficial phytochemicals found only in plant foods and contains only a couple of grams of fiber. But I firmly believe that a carbohydrate-restricted plan that includes the high-fiber plant foods listed above can be a very heart-healthy way to go.
1. Tay, J., et al. Metabolic effects of weight loss on a very-low-carbohydrate diet compared with an isocaloric high-carbohydrate diet in abdominally obese subjects. J Am Coll Cardiol, 2008. 51:59-6
2. Volek, J.S., et al. Dietary carbohydrate restriction induces a unique metabolic state positively affecting atherogenic dyslipidemia, fatty acid partitioning, and metabolic syndrome. Prog Lipid Res, 2008, doi: 10.1016/j.plipres.2008.02.0033.
3. Hayek, T, et al. Dietary fat increases high density lipoprotein (HDL) levels both by increasing the transport rates and decreasing the fractional catabolic rates of HDL cholesterol ester and apolipoprotein (Apo) A-I. J Clin Invest, 1993; 91(4);1665-16714.
4. Siri-Tarino, P.W., et al. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr doi: 10.3945/ajcn.2009.27725
Franziska Spritzler, RD, CDE