Comparative Effects of Time-Restricted Eating and the Ketogenic Diet on QRISK3-Assessed Cardiovascular Risk in Individuals with Obesity: A Longitudinal Analysis of Metabolic, Anthropometric, and Lifestyle Factors

Background/Objectives: Obesity remains a major public health concern, and effective dietary strategies for reducing cardiovascular risk are still under investigation. This interventional non-randomized study aimed to evaluate the short-term effects of the modified ketogenic diet (KD) and time-restricted eating (TRE) on cardiovascular risk, as assessed by the QRISK3 score. Methods: Forty-nine adults with obesity were assigned to either the KD (n = 23) or TRE (n = 26), based on voluntary presentation to a nutrition clinic. Interventions were monitored by a certified clinical nutritionist over 12 weeks. Anthropometric parameters, metabolic markers, and QRISK3 scores were measured at baseline and post-intervention. Results: Both dietary approaches led to significant reductions in body weight and QRISK3 scores. However, the KD resulted in more pronounced improvements in the lipid profile, systolic blood pressure, and glycemic control. Interaction analysis suggested that older participants and those with a higher baseline risk benefited more from the KD. Conclusions: Over 12 weeks, both diets improved cardiovascular risk and metabolic markers in individuals with obesity. The modified diet ketogenic dietary pattern showed more pronounced short-term benefits in the lipid profile, blood pressure, and glycemic control. These results suggest its potential utility in clinical practice, though long-term effectiveness and safety remain to be established.