This new network meta-analysis of nearly 12,000 adults reveals that the size of your energy deficit, not your fasting schedule, determines how much weight you shed and how your metabolism improves.
Overview
- What did they test? The effects of continuous energy restriction (CER) versus four intermittent fasting (IF) patterns for effects on weight, body composition, blood pressure, lipids, and glycemic markers.
- What did they find? Weight loss was associated with the calorie deficit: severe CER (–11.5 kg) > moderate CER (–6.1 kg) > mild CER (–4.3 kg). Among IF diets, alternate-day fasting (–5.1 kg) ranked highest, matching moderate CER when calories were matched. Metabolic improvements followed similar patterns.
- What does it mean for you? Pick the diet style you can stick with whether that’s continuous or intermittent. As long as you have a calorie deficit, you’ll get similar weight loss and health benefits.
What’s the Problem?
Both continuous energy restriction (CER) and intermittent fasting (IF) achieve weight loss by reducing overall caloric intake; however, the specific effect of diets on body weight, cardiometabolic health, and adherence remains unclear 1 2. Traditional CER, which typically includes a 500–750 kcal daily deficit, has a track record for weight loss but often falters on long-term adherence and may require intensive behavioral support to sustain 3.
IF is an umbrella term for different variations of fasting regimens, but the three most mentioned variations are the following: alternate day fasting (ADF), the 5:2 diet, and time-restricted eating (TRE). The first two are self-explanatory. TRE has more variation within it, but generally confines all caloric intake to a specific feeding window (e.g., 4, 6, 8, or 12 hour windows) 4.
Systematic reviews and meta-analyses comparing IF and CER have shown conflicting results. One review concluded that IF lowers weight but was not superior to CER 5. Another study found that IF was not better than CER for fat and weight loss, but IF caused greater lean-mass losses 6. A recent network meta-analysis ranked ADF highest among diets for weight loss, yet still detected no statistical edge over CER once calories were matched, and adherence decreased over time across all types of diets 7.
The current study under review was a network meta-analysis, adjusted for trial duration, and based on scores to show the probability each diet is best. By pooling 167 RCTs and applying definitions of mild, moderate, and severe CER alongside four IF patterns, their goal was to isolate whether fasting timing adds any benefit beyond calorie deficit and to clarify which diet performs best for weight loss and metabolism.
Purpose
To compare the effects of energy-restriction magnitude from different meal-timing patterns on weight loss and metabolism.
Hypothesis
Weight loss and metabolic improvements are driven by the extent of calorie restriction, not by whether the diet is continuous or intermittent.
