Chronic Ketogenic Low Carbohydrate High Fat Diet Has Minimal Effects On Acid–Base Status In Elite Athletes

This study examined whether following a ketogenic (very low-carb, high-fat) diet for three weeks would change the acid-base balance in the blood of elite athletes. Researchers were interested in this because some people worry that ketogenic diets might make the body too acidic, potentially affecting performance and health. They compared 24 elite race walkers who followed either a ketogenic diet, a periodized carbohydrate diet (varying carb intake based on training), or a traditional high-carbohydrate diet.

The researchers measured blood pH (acidity), bicarbonate levels (which help buffer acid), and lactate levels before and after exercise testing. They also calculated how much acid each diet would theoretically produce in the body based on food intake. As expected, the ketogenic diet did produce significantly more acid than the high-carbohydrate diet when calculated from food composition.

However, the actual blood measurements told a different story. Despite the higher acid production on paper, athletes following the ketogenic diet showed no meaningful differences in their blood acid-base status compared to those eating high-carbohydrate diets. Their blood pH, buffering capacity, and lactate levels remained essentially the same both at rest and after intense exercise.

The researchers concluded that the body's natural regulatory systems - particularly breathing and kidney function - are powerful enough to maintain proper acid-base balance regardless of diet type, at least in well-trained athletes. This finding suggests that concerns about ketogenic diets causing problematic acidity may be overstated in healthy, active individuals. For patients considering ketogenic approaches for metabolic health, this research indicates that short-term acid-base disruption is unlikely to be a limiting factor, though individual monitoring and medical supervision remain important for optimal outcomes.