Does soda add belly fat?

Do sweet drinks cause belly fat? Fat around abdominal organs is much more active metabolically than the fat under our skin, and poses additional risk for diabetes, heart disease and stroke above and beyond the risk seen with being overweight.

And while fat distribution is influenced by age and genetics a growing body of evidence suggests dietary choices, and especially sugary drinks increase fat accumulation in the worst possible locations of our anatomy.

A study from the University of California at Davis showed that drinking 25 percent of daily calories (which is quite a lot) in fructose for 10 weeks increased triglycerides and cholesterol, caused insulin resistance and belly fat accumulation. 

A recent study found that even moderate consumption of sugary drinks led to measurable undesirable effects after just three weeks: Belly fat accumulated, fasting glucose levels and inflammation markers rose, and the lipid profile changed when volunteers drank what amounted to just 1 can of soda a day.

Another study in the journal Obesity, following 800 people, found that drinking sugary drinks was associated with significantly more belly fat and wider waistlines.

A new study in the American Journal of Clinical Nutrition adds to this body of evidence with a rather long-term study, in which a small group of overweight people were assigned to drink cola, skim milk, diet cola or water, while fat distribution and metabolic markers were monitored.

Drinking soda for 6 months 

The Danish study involved 47 healthy participants – it’s definitely a small study.  The participants drank 1 liter – about 33 ounces -- of regular cola, skim milk, diet soda or water daily, for 6 months.

The total caloric intake didn’t differ between the participants, and all the participants gained just about the same amount of weight (almost 3 pounds).

On the other hand, the amount of fat in the liver, abdominal organs and muscle increased significantly in the regular soda group, while it remained unchanged in the other study groups. (Fat was measured by an MRI technique.)

Blood pressure and triglycerides also rose among the soda drinkers. 

The soda belly-fat connection

Why would soda lead to preferential accumulation of belly fat? There’s some evidence that the fructose content of the drink is to blame.  The simple sugar fructose is metabolized in our body in a way that promotes fat production, raises triglycerides and affects cholesterol levels.  Soda is made with either table sugar, which is 50 percent fructose, or High Fructose Corn Syrup (HFCS), which is about 55 percent fructose.  Fructose is absent in milk, diet soda and of course water.

Diet soda was off the hook in this study, but other observational studies have shown that diet soda is linked with obesity, type 2 diabetes and the metabolic syndrome.

Is 33 ounces of soda a lot?

While 1 liter or 33 ounces of soda sound like a lot, the authors, led by Maria Maersk, present an embarrassing comparison to average American intakes.  The typical young American (12-29y) drinks 60 ounces of sugary drinks-a-day; the average American guzzles 16.  Fast food eateries offer 42-ounce and 64-ounce sodas.  Unfortunately, 33-ounces-a-day isn’t out of the realm of what people actually do.

Soda, not beer, might be inducing our belly expansion.

Dr. Ayala 

Full disclosure: I’m vice president of product development for Herbal Water, where we make organic herb-infused waters that have zero calories and no sugar or artificial ingredients. I’m also a pediatrician and have been promoting good nutrition and healthy lifestyle for many years.