A comprehensive review of clinical trials reveals strong evidence that most diets achieve comparable modest weight loss and improvements in cardiovascular risk factors over six months compared to usual eating patterns.
By the 12-month mark, weight loss typically diminished across diets, and cardiovascular benefits largely faded—except for the Mediterranean diet, which maintained a small but significant reduction in LDL (“bad”) cholesterol. For short-term gains, experts recommend selecting a diet that suits your lifestyle without fixating on comparative effectiveness.
Global obesity rates have nearly tripled since 1975, yet no large-scale analysis had previously compared popular diets head-to-head for weight loss and heart health markers like blood pressure and cholesterol.
International researchers addressed this gap by analyzing 121 randomized controlled trials involving 21,942 overweight or obese adults (average age 49). Participants followed named diets or control diets, with outcomes adjusted for study design and quality variations.
Diets were categorized by macronutrient composition (low-carb, low-fat, moderate macro—balancing slightly more fat and fewer carbs than low-fat) and 14 branded programs (e.g., Atkins, DASH, Mediterranean).
Versus usual diets, low-carb and low-fat options yielded similar weight reductions of 4-5 kg and lowered blood pressure at six months; moderate macro diets showed slightly smaller effects.
Among branded diets, Atkins, DASH, and Zone produced the strongest results (3.5-5.5 kg loss and blood pressure drops) at six months. No diet significantly boosted HDL (“good”) cholesterol or lowered C-reactive protein (an inflammation marker).
By 12 months, weight loss declined on all diets, and benefits vanished except for Mediterranean’s sustained LDL reduction.
While acknowledging limitations like study heterogeneity, the researchers affirm the analysis’s robustness through exhaustive searches and rigorous methods. With moderate certainty, macronutrient-manipulating diets offer modest short-term weight loss and blood pressure improvements, but differences are minor.
Individuals can thus prioritize preference for short-term benefits, the authors conclude.
“This vast array of diets offers choice but no definitive winner,” note Monash University experts in an accompanying editorial. They urge shifting focus from diet selection to sustainable weight maintenance.
Embrace food-based guidelines: prioritize vegetables, legumes, and whole grains while cutting sugar, salt, and alcohol for lasting health.
