Are water-only diets safe?

Cutting down food to lose weight is at the core of most diets, but now some people are taking food out of the equation all together. The trend: ‘water fasting’ whereby you drink nothing but water or other non-caloric drinks for a specific amount of time.

Tipping the scales at 300 and triple bypass surgery under his belt, Richard Nall decided to try several rounds of the fasting. “I just finished a two-week fast during which time I drank nothing but water and coffee and nothing else,” he says.

Look online and you can easily find people ‘drinking up’ for anywhere from 24 hours …even 20 to 30 days. And some people do the food-free stints multiple times.

Nutritionist Mascha Davis is a spokesperson for the Academy of Nutrition and Dietetics. She doesn’t like the liquid plan, saying, “Any time that we do something like that we risk disrupting our metabolism. There’s a high chance of rebound weight gain and if people do this for a lengthy amount of time there can be a lot of other health risks involved.”

Davis points to risks like low blood sugar for diabetics, possible electrolyte imbalance or the potential loss of muscle mass if done for an extended amount of time.

We did find some studies talking about potential benefits of fasting in terms of hypertension, arthritis and cancer treatments.
We asked Davis about those. “What I can say is that it seems like there’s some exciting findings coming out when it comes to things like cancer or chemotherapy. But in terms of weight management, the long-term studies that I’ve seen don’t support very much benefit.”

Davis doesn’t recommend it, period, but says if it is done it should be under medical supervision.

Nall just weighed in at around 220 pounds. He says he is now off his blood pressure medication and insists he is not going it alone. “Both my cardiologist who did the surgery on my heart and my general practitioner, who’s a brilliant man, verified, validated the water fasting,“ he tells us.

When Nall isn’t fasting, he follows a plant-based diet, which is common for a lot of fasters we found online. Davis says it’s hard to say whether the results in some of the stories are from the fasting or from the change in diet. Nall says he sees it as a combo of fasting, diet and exercise.

As for the research into the possible benefits, Davis points out that while it is exciting it is early and that some of the research is on mice.

She also says she is worried about the psychological impact the fasting could have on those at risk for eating disorders.