The term "low carb" is not easily defined. Low as compared to what? The Recommended Dietary Allowance (RDA) for minimum carbohydrate intake, as set by the Institute of Medicine's Food and Nutrition Board, is 130 grams per day. This is the level which dietitians are taught to instruct people never to go below "in order to maintain brain function." This recommendation is based on the central nervous system's daily requirement for about 130 grams of glucose (NOT carbohydrates). Further confusing the issue, the Reference Daily Intake (RDI) for carbohydrate (also set by the Food and Nutrition Board) "to meet the needs of 97-98% of healthy individuals" is 300 grams for a diet containing 2000 calories and 375 grams for a 2500- calorie diet (You can see find these numbers in the Daily Values section on any nutrition facts label). Why the disparity? Because the Board recommends that carbohydrates make up 45-65% of caloric intake. For someone eating 2000 calories daily, going with the average of 55% , this is 1100 calories or 275 grams of carbs. Not exactly 300 grams, but close. I'm not sure why the Board didn't set the value at 250 grams, or 45% of calories, since this would still be more than sufficient to meet people's needs and is nearly double the RDA. But for whatever reason, the RDI I is set at 300 grams.
So is low carb anything below 300 grams, then? Well, few people would argue that eating 280 grams of carbs a day constitutes a low-carbohydrate diet. Most would consider less than 150 grams to be low carb, or moderately low carb at the upper limit. Of course, there's a big difference between 15 grams of carbohydrates vs. 149 grams per day. Also, are we talking about total carbs or digestible ("net") carbs, calculated by subtracting the fiber from the total carb content? Some people count total carbs (starch, sugar, and fiber), some count only digestible carbs, and some follow the recommendation of the American Diabetes Association to subtract half the carbs from the total if the item in question has more than 5 grams of fiber. I prefer counting only digestible carbs, and I eat about 60 grams per day, which equates to 80-90 grams total carbs. More important for me is the amount of carbohydrates per sitting, because anything over 20-25 grams of digestible carbs usually results in higher blood sugar readings than I'm comfortable with.
Is there a carbohydrate level that is too low to be considered healthy? That depends on which studies you feel are reliable and, I would argue, your feelings about carbohydrate restriction. There also isn't a lot of research out there on low carbohydrate diets that provide enough calories; most were conducted on subjects consuming very-low-calorie diets, anywhere from 500-1000 calories per day. (There was also at least one that provided excessive calories, which opens up a whole other issue). Another problem is the short duration of some of the studies, since it typically takes time for the body to acclimate to lower carbohydrate intake. As long as there is sufficient protein and fat in the diet, gluconeogenesis will provide additional glucose to be used to fuel certain portions of the brain, the retinas, the red blood cells, and the kidneys, and ketone bodies produced from the metabolism of fat will supply energy for the cells and organs that don't require glucose (all of the others, including parts of the brain).
There is research suggesting that a minimum of 50 grams of carbohydrates per day is required to maintain proper conversion of the thyroid hormone T4 to the active form, T3, and to prevent excessive production of reverse T3. However, there is a fair amount of anecdotal evidence that some people can go well below 50 grams without developing this problem. Those who follow Atkins and other low-carb plans typically start on an induction phase of less than 20 grams daily for several weeks or months, gradually adding back carbs as they approach maintenance, and many appear to maintain normal thyroid function while eating very little carbohydrate.
Daily carbohydrate intake of 20 grams per day on a long-term basis may be too low for some people, although fine for others. I personally know a few people who comfortably subsist on this amount or less. Dr. Richard Bernstein is an example of a person with Type 1 diabetes who has strictly maintained a 30-gram-carb-per-day intake for over 40 years with no apparent ill effects nor any diabetes-related complications like retinopathy, neuropathy, nephropathy, or cardiovascular disease. He also appears fit and still maintains a busy practice at the age of 76. Obviously, this very-low-carbohydrate diet is definitely working well for him, as I know it has for many others.
So back to the original question: How low is too low? As with almost everything else, how one responds to carbohydrates is highly individualized. Some people will do well on 30 or fewer grams of carbs indefinitely, while others may feel best eating 100 grams or more, and most will fall somewhere in between. Optimal carbohydrate intake is fluid and may vary from day to day, month to month, and year to year. We need to take into consideration how we feel energy-wise as well as how various carbohydrate levels affect our weight, blood sugars, blood lipids, and thyroid hormones.
I don't think it's right to assign a minimum carbohydrate requirement of 130 grams for brain function -- some of the most brilliant doctors and scientists out there consume far less than this -- and I believe 300 grams is too high for the vast majority of adults, although I do have friends who regularly consume 300-400 grams daily and manage to stay in amazing shape with great energy and normal labs. I respect the right of every person to make the choice about what is right for himself or herself, and I would never try to "push" low-carbing on anyone who wasn't interested. However, I feel strongly that carbohydrate restriction should be presented as a healthy option, given its many benefits and the success that so many have had with it. While I'm fortunately not the only dietitian who feels this way, I'm definitely in the minority. I remain hopeful that the powers that be will accept carbohydrate restriction as a legitimate way of eating someday very soon!
1. Panel on the Dietary Reference Intakes for Macronutrients, Institute of Medicine. Dietary reference intakes for energy, carbohydrates, fiber, fat, fatty acids, cholesterol, protein, and amino acids. Washington, DC: National Academies Press, 2002.
2. Burman KD, et al: Glucose modulation of alterations in serum iodothyronine concentrations induced by fasting. Metabolism ,1979 Apr;28 (4): 291–299
3.Volek JS, et al. Body composition and hormonal responses to a carbohydrate-restricted diet. Metabolism, 2002 Jul; 51 (7): 864-870.
This week in our outpatient nutrition clinic, a patient talked to me excitedly about juicing "because all those antioxidants can really help with inflammation!" I've never been a fan of fruit juice -- too many calories and carbs that quickly raise blood sugar. Plus, your brain doesn't process liquid calories and carbs the same way as it does whole foods that are chewed and digested, so you end up hungry regardless of how much energy you've consumed. But could juicing possibly help with inflammation?
Research has consistently demonstrated a link between inflammation and most chronic diseases, including diabetes, obesity, arthritis, and cardiovascular disease, as well as autoimmine conditions like lupus, celiac disease, and Hashimoto's thyroiditis. The omega-3 fats found in certain fish (salmon, sardines, herring, mackerel) are universally accepted as having anti-inflammatory properties. But aside from fish, how should we be eating to reduce inflammation, relieve symptoms, and prevent disease progression? There are different schools of thought on this. Some physicians and nutrition professionals recommend a plant-based or vegan diet for cardiovascular disease; the American Diabetes Association favors a relatively high-carb eating plan for diabetes management. But I'm convinced that a low-carb, Paleolithic/Primal diet is optimal for decreasing inflammation.
Why is a low-carb, Paleo way of eating the way to go? Because it:
1. Lowers insulin levels: Excessive amounts of insulin produced in response to high carbohydrate intake results in systemic inflammation. With carbohydrate restriction, blood sugar rises only minimally after a meal and insulin levels decrease considerably.
2. Eliminates gluten: Gluten is regarded by many progressive health practitioners as an inflammatory substance, and there is a growing body of evidence to support this. It's especially problematic for anyone suffering from Hashimoto's disease or other autoimmune conditions. In addition, their phytates can bind to minerals (this is particularly true for whole grains), preventing their absorption.
3. Promotes high intake of grass-fed meat and naturally raised poultry and eggs: Cows that eat grass instead of grains produce meat that is much higher in omega-3 fats. Organic chickens have higher omega-3 content than those raised on factory farms. In addition, eating naturally raised animals that are not given hormones and antibiotics may also contribute to a reduction in inflammatory markers. Important side benefits are the humane treatment of livestock and a more favorable impact on the environment.
4. Focuses on whole foods and eliminates processed foods, including unhealthy oils/fats: Processed foods have been altered from their original state and can cause an inflammatory response in many people. Smart Balance, Promise, and other "healthy" margarines contain genetically modified canola and soybean oil, which are not natural (and therefore not healthy) foods. In addition, they are high in omega-6 polyunsaturated fats, which can increase inflammation if consumed in excess, which the majority of Americans do. I won't even go into partially hydrogenated oils except to say that there is absolutely nothing positive to say about them.
As far as juicing goes, I can't argue that there are antioxidants in juice. However, fruit juice's negatives (high in sugar, low in fiber, and almost certain to raise insulin levels due to being way too easy to consume in excess) outweigh its positive (contains antioxidants). If we're talking vegetable juice, there will obviously be less sugar consumed and therefore a lower insulin response, but it's still a more concentrated source of carbs than whole vegetables. And there are more antioxidants in whole fruits and vegetables than there are in the juice anyway.
So would I recommend juicing as an aid to reducing inflammation? No way! Low-carb, Paleo/Primal with plenty of whole vegetables beats it by a mile!
Dr. Art Ayers has a great blog called Cooling Inflammation, and he also believes in a low-carb approach. He was recently a guest on Jimmy Moore's Livin' La Vida Low Carb podcast, so be sure to listen to it when you get a chance. And check out the list of 11 anti-inflammatory foods from the D Life website. Looks pretty Paleo to me!
1. Forsythe CE, Phinney SD, et al. Comparison of low fat and low carbohydrate diets on circulating fatty acid composition and markers of inflammation. Lipids, Jan 2008
2. Seaman DR. The diet-induced pro-inflammatory state: A cause of chronic pain and other degenerative diseases?J Manip Physiol 2002
3.Interesterification, Mary G. Enig, PhD. Weston A Price Foundation website: http://www.westonaprice.org/know-your-fats/556-interesterification
I'm keeping it short today since we're making the final move into our new place and may not have Internet access for a while. Fortunately, I've downloaded a lot of podcasts onto my Ipad -- will make unpacking much more enjoyable!
I've been eating some very basic Paleo/Primal foods this week, and it's going very well so far. I'm eager to try preparing some more elaborate recipes soon. However, since our new refrigerator won't be delivered for a few days, a good portion of my meals will be eaten away from home. So I thought I'd post a few ideas for making great low-carb, Paleo/Primal dining choices, beginning with choosing the right restaurant.
Here's a regional list of restaurants that serve Certified Humane (no antibiotics, free-range, naturally raised) poultry, meat, dairy, and/or eggs. Check out the ones in your area, and feel free to add any others you know and like in the comments section below. I know there are a lot more out there! Very easy to make these meals low-carb by replacing the bread, pasta, and potatoes with extra grilled veggies or a large salad.
The following are my favorite places that serve at least one low-carb, Paleo/Primal-friendly entree (hopefully a few on the list have locations near you!) and what I recommend ordering from each. Enjoy!
1. Chipotle Everything here is wonderful! 100% of the pork, 80% of the chicken, and 85% of the beef (100% for barbacoa) served at Chipotle is naturally raised, and their goal is to eventually offer only 100% organic/naturally raised meat and poultry.
Recommendation: Chicken, pork, or beef salad with lettuce, sauteed green peppers and onions, pico de gallo, and a generous scoop of homemade guacamole.
2. Ruby's Diner Earlier this year, this '50s-style diner began using only naturally raised beef in all its restaurants. Chicken is still conventionally farmed, however.
Recommendation: Ruby's burger in lettuce wrap or chopped steak, large salad with oil and vinegar
3. Wood Ranch BBQ and Grill Select entrees at Wood Ranch use poultry that's free-range and naturally raised.
Recommendation: Roasted free-range half chicken or free-range turkey sliders, large salad with oil and vinegar
4. Panera Bread Although known for its sandwiches and baked goods, there are a number of naturally raised chicken salads available at Panera.
Recommendation: Grilled Chicken Caesar Salad or Chopped Chicken Salad
Franziska Spritzler, RD, CDE