Do Carbohydrates Help or Hurt Weight Loss?

Carbohydrates have been vilified over the years.  The Adkin’s diet and other low carbohydrate diets have highlighted carbs as the primary cause of our obesity problem in the United States.  Is there any truth to this claim or is this just hype to sell books and low-carb foods?  

Research On Carbohydrates:  

1. Cutting back on sugar and simple carbohydrates.  Simple carbohydrates are the easiest to remove from your diet.  In fact, sugar is the single worst ingredient you can eat if you are trying to lose weight.  Outside of calories, there is no benefit to eating sugar and simple carbohydrates.  One study showed a tie between high fructose corn syrup consumption and obesity​[1]​.  Other studies also support this belief​[2]​,​[3]​,​[4]​,​[5]​.  It only makes sense that sugar and high fructose corn syrup can cause obesity since they are readily absorbed and require little work to digest.  
2. Sugar-sweetened beverages increase your risk for diabetes and heart disease.  Studies show that increased sugar consumption is strongly associated with the risk of heart disease and other cardiac equivalents such as type 2 diabetes​[6]​,​[7]​,​[8]​,​[9]​.  Although this is more complex than sugar alone and genetics play a part, This leans toward suggesting a limitation for 10% or less of our calories from simple sugars.  
3. Eat more unrefined carbohydrates.  I have already discussed the evils of simple sugars.  Unrefined or less refined sugars contain more fiber and slow the absorption of sugars.  Refined carbohydrates are usually sugar or grains that have been stripped of their fiber.  Studies show that refined carbs can spike blood sugar rapidly and that fiber slows this down.  For more information on fiber, see my page on fiber and weight loss research.  
4. Going Lower Carb.  I am not a low-carbohydrate guy, but lower-carbohydrate and higher protein diets make sense.  Beyond the Adkin’s diet, plenty of studies show that lower carb and higher protein diets can help you lose weight as a standard low-fat diet[10],[11],[12],[13].  There is also an excellent study from the New England Journal which showed that multiple types of diets can be successful if there is a calorie deficit but that they should be tailored to the specific patient[14].  The key concept is that a traditional higher carb and low-fat diet is harder to maintain for most so I would recommend that you tailor a diet to your needs.  If you find the regular diet too hard to sustain, consider a higher protein and lower carbohydrate diet.  

Recommendations on Carbohydrates:

1. Avoid high fructose corn syrup.  There is no nutrient value to most of the foods that have this added if you exclude calories.  
2. Avoid simple sugars and sugar-sweetened juices.  There is no nutrient value to most of the foods that have this added if you exclude calories.
3. Avoid fruit juices.  Eat whole fruits instead so you get the fiber also.  
4. Eat plenty of fiber.  Fiber will slow down the digestion and absorption of calories.  

The bottom line: Carbohydrates are not needed to function but we function more efficiently with them. Eat more complex carbohydrates that are high in nutrients and fiber.