Belly Fat and Common Food Additive Tied to Kidney Disease Risk

New York, NY (November 1, 2013) – Losing belly fat and cutting back consumption of phosphorus found in processed foods and dietary protein may reduce risk for developing kidney disease, according to a new study published in the November issue of the National Kidney Foundation's American Journal of Kidney Diseases.

For the first time, researchers found that diminishing waist circumference and consuming less dietary phosphorus were linked with reduced levels of albuminuria, or protein in the urine — one of the earliest signs of kidney disease.

“Other studies have suggested that once diagnosed with kidney disease, weight loss may slow kidney disease progression, but this is the first research study to support losing belly fat and limiting phosphorus consumption as a possible way to prevent kidney disease from developing,” said Joseph Vassalotti, MD, Chief Medical Officer at the National Kidney Foundation.

Key Findings

Researchers led by Alex Chang, MD, MS of Johns Hopkins University, examined the association between weight loss, phosphorus intake and urine protein levels in 481 participants, based on the PREMIER study of lifestyle modifications in overweight-obese adults. After six months, on average, study participants decreased their belly fat by 4.2cm and experienced a 25% reduction in urine protein. Additionally, a 314 mg reduction in phosphorus excretion resulted in an 11% decrease in urine protein.

In the United States, phosphorus is added to many processed foods to help enhance their flavor and shelf life. High levels of phosphorus are also naturally found in animal, dairy, and vegetable proteins, according to Chang. Due to its chemical composition, the phosphorus found in processed foods – which accounts for up to 30% of the phosphorus consumed in the U.S. diet – as well as the phosphorus contained in animal proteins is more readily absorbed by the body than plant-based phosphorus, which is harder for humans to break down.

“A good rule of thumb is that if the food comes in a package, it’s likely to be high in phosphorus. Approximately 90% of phosphorus additives are absorbed by the body. This study suggests limiting the amount of processed foods in your diet may be an easy way to reduce your risk of developing kidney disease,” said Dr. Vassalotti.

Phosphorus – Where is it Hiding on the Supermarket Shelves?

Phosphorus has no taste or smell, yet it lurks in many places. It is naturally abundant in protein and any food that has undergone processing may contain high levels. According to the National Kidney Foundation, it’s important to start by looking for any ingredients that contain the root letters “PHOS,” as this indicates phosphorus additives. Yet, phosphorus isn’t always labeled on the packaging, so it’s also important to recognize some key culprits:

  • Processed foods – dark colas, cereals, flavored waters
  • Dairy products – cheese, milk, cream, ice cream and yogurt
  • Animal protein – deli meats, meat tenderizers, organ meats, oysters and sardines
  • Other sources – dried beans, lentils, peas, nuts and seeds (including peanut butter and other nut butters), cocoa (including chocolate-based drinks and puddings)

The National Kidney Foundation is the leading organization in the U.S. dedicated to the awareness, prevention and treatment of kidney disease for hundreds of thousands of healthcare professionals, millions of patients and their families, and tens of millions of Americans at risk. For more information, visit www.kidney.org.