Sarah Giardenelli, ND, MSOM, LAc, is a certified naturopathic doctor and licensed acupuncturist.

Pasta: a favorite food worldwide. But, according to a recent Washington Post article there has been a significant decline in pasta sales in recent years – even in Italy! – correlating with trends of low-carb diets and gluten free eating.  So, is the fear of carbohydrates is really valid?  Well, the answer is complex because our biology is complex.

Typically, the first thing most people think about when they need to lose weight is to cut back on the carbs.  Common assumptions are that carbs spike blood sugar and insulin, cause inflammation, and are not as important in the diet as fat and protein.  Well, let’s start by getting one thing clear: whole, minimally processed carbs – just like protein and fats – are essential to health.

While it is true that carbs increase insulin levels after eating, this is normal and leads to satiety.  And, on its own – without other imbalances in the body – it will not lead to fat gain.  Carbs can be inflammatory, but so can any other food – it really depends on each individual.  Food sensitivities and the person’s level of intestinal health need to be accounted for.   The processing of the carb is also a key factor to look at when evaluating whether it will cause inflammation in the body.  The highly hybridized proteins of wheat are very difficult to digest.  Evidence is mounting that this is a cause of inflammation in the intestines, even in people without Celiac disease, termed non-Celiac gluten sensitivity.  So, it is important to opt for whole, unrefined, nutrient-dense carbs like whole grains, fruits, vegetables and beans.

Is the low-carb diet a fad?  It’s actually not – low-carb diets have been around for years!  The first low-carb book was published in 1862 and used by many physicians as early as the 19th century.  Lowering carbs is commonly recommended as a tried and true strategy for weight loss.  The low fat diet and high carbohydrate diet that was advocated for years until recently as public health policy was based on limited evidence, whereas the weight of research to date points towards a low carbohydrate diet as being more advantageous for weight loss and cardiovascular health in comparison. (1)

What defines a low carb diet really depends on who you talk to.  A low carb diet is generally considered to be a daily limit of 240 – 520 calories from carbs or 60 – 130 grams of carbs. (2)  Current Dietary Guidelines for Americans recommend that carbohydrates make up 45 – 65 percent of total daily calorie intake.  If consuming a 2,000 calorie diet, this would be 900 – 1,300 calories from carbs, or, 225 – 325 grams of carbs per day.

While many people do lose weight with a low carb diet, this may or may not be due to the low carb diet aspect of the diet.  And, it may not be an appropriate approach to eating for many people over the long term; it might have more to do with the amount of protein consumed. (3)  Low carb diets do often help with immediate weight loss by modulating hormone levels that render it difficult to lose weight. However, the research hasn’t demonstrated the differences between low carb and other types of diets over the long-term.

One concern with the research comparing low carb diets to other diets is that the protein intake isn’t always matched between study participant groups.  The advantages with higher protein diets are that protein consumption increases the thermic effect in our bodies, leads to prolonged satiety, and helps retain lean muscle mass when dieting. (3)  One study that did match protein compared this with moderate carb diet (40% of calories from carbs) and very low carbohydrate/ketogenic diet (5% of calories from carbs).  The group with high protein and moderate carbs showed a small, but not significantly significant, tendency to lose more body fat compared to the low carb group.  While both diets improved insulin sensitivity, the ketogenic diet caused increased in inflammatory markers and study participants felt fatigued. (3)

Other researchers compared four different types of diets: 1) normal protein, normal carb; 2) normal protein, low carb; 3) high protein, low carb; 4) high protein, normal carb. The high protein groups lost the most weight and varied levels of fats and carbs consumption didn’t change body composition. (4)

Most people do well with some carbohydrates in their diet, but the type of carbohydrate and the amount of protein consumption can make a big difference.  Others might need to decrease their carbohydrate consumption slightly.  There are a few people – like elite endurance athletes – who do better on a very high carbohydrate diet, but most of us are not in this category.  But, on the other hand, there are some elite athletes who do well on a low carb, high protein diet.  There are some patients – such as those who are sedentary and struggling to lose weight due to metabolic issues – who often do well with a low or very low carbohydrate diet for several months as they transition to a more active lifestyle.

There are circumstances where a low carbohydrate diet should be avoided.  Such is the case in pregnancy as carbohydrates are essential for fetal brain development and growth.  Most experts recommend that at least 30% of calories come from carbohydrates during pregnancy.

A patient with hypothyroidism is also not recommended for a low carb diet.  This is because insulin is needed for the conversion of inactive T4 to active T3.  On a low carb diet, insulin levels can tend to be very low. (5)  Those suffering from the effects of high stress with fatigue and anxiety are also not ideal candidates for a low carb diet.  This is because a high protein diet may reduce the calming neurotransmitter GABA and carbohydrates seem to improve the body’s response to stress. (6)

So, as you can see, carbohydrate needs do really vary from person to person.  In my opinion, carbs should not be feared, but rather optimized.  Look at the types of carbs you’re eating and opt for the whole, unrefined, nutrient-dense varieties.  Work with a health professional – like a registered dietitian or a naturopathic doctor – who can help you to determine the optimal macronutrient intake for your unique needs.

REFERENCES

  1. Gunnars, Kris. 6 Reasons to Stop Calling Low-Carb a “Fad” Diet. Authority Nutrition. [Online] [Cited: 9 2, 2015.] http://authoritynutrition.com/6-reasons-to-stop-calling-low-carb-a-fad/.
  2. Low-carb diet: Can it help you lose weight? Mayo Clinic. [Online] [Cited: 9 2, 2015.] http://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/low-carb-diet/art-20045831?pg=1.
  3. Pierre, Brian St. Carb controversy: Why low-carb diets have got it all wrong. Precision Nutrition. [Online] [Cited: 9 2, 2015.] http://www.precisionnutrition.com/low-carb-diets.
  4. Relatively high-protein or ‘low-carb’ energy-restricted diets for body weight loss and body weight maintenance? Soenen S et al. 107, s.l. : Physiol Behav, 2012 , Vol. 3.
  5. Laura Schoenfeld, RD. Is a Low-Carb Diet Ruining Your Health? Chris Kresser. [Online] 8 26, 2014. [Cited: 9 2, 2015.] http://chriskresser.com/is-a-low-carb-diet-ruining-your-health/.
  6. Lara Briden, ND. Gentle Carbs for GABA, Cortisol and Adrenal Health. Lara Briden. [Online] 2 10, 2013. [Cited: 9 2, 2015.] http://www.larabriden.com/gentle-carbs-for-gaba-cortisol-and-adrenal-health/.

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