Low Energy Diets for Obesity and CKD (SLOW-CKD Randomized Feasibility Study)

Low energy diets (LEDs) may slow disease progression; however, their effects are under researched in chronic kidney disease (CKD). This study evaluated the safety and feasibility of an LED weight management program in adults with obesity and CKD.

This multicenter 6-month randomized controlled trial (RCT) involved adults with CKD Kidney Disease: Improving Global Outcomes stages G1 to G3b, obesity, and proteinuria, randomized 1:1 into 2 groups. The LED group followed a 3-month 800 to 900 kcal/d LED, with dietitian support, then a 3-month weight maintenance phase with exercise and healthy eating support. The usual care (UC) group received standard clinic weight loss support. Primary outcomes were safety (serious adverse events [SAEs]) and feasibility (≥2 of recruitment rate ≥ 25%, LED group retention rate ≥ 75%, and ≥ 30% of LED group achieving ≥ 10 kg weight loss at 3 months). Secondary outcomes included changes in anthropometry, clinical measures, patient-reported outcomes, and participant experiences.

Forty-nine participants (median age 51 years, 57% male) consented. SAEs were low and comparable as follows: 2 in the LED group (hypoglycemia and acute kidney injury) and 2 in the UC group (hypoglycemia), all requiring hospitalization. Feasibility was met for recruitment (46%) and weight loss (46% achieved ≥ 10 kg loss) but not for retention (67% retained). At 6 months, median (IQR) weight change was -9.0 kg (-12 to -7) in the LED group and 0 kg (-4 to 2) in the UC group (P < 0.001).

LEDs under professional guidance are safe and feasible for weight loss in adults with obesity and CKD Kidney Disease: Improving Global Outcomes stages G1 to G3b. A definitive RCT to assess their effects on clinical outcomes and CKD progression is warranted.