Struggling to drop body fat without sacrificing your hard-earned muscle? It's the classic dilemma for any serious lifter. A calorie deficit is necessary for fat loss, but it puts your muscle mass at risk. So, how do you get leaner while keeping your strength and size?
A recent study published in the International Journal of Sport Nutrition and Exercise Metabolism investigated a powerful three-pronged strategy: combining a high-protein diet, time-restricted eating (TRE), and resistance training. The results suggest this could be a game-changing combination for optimizing body composition.
Disclaimer: This review is based on the abstract of the study, as the full text was not publicly available.
The Study: Pitting Four Strategies Against Each Other
Researchers wanted to see what happens when you combine these popular methods. They took 32 young women with overweight (BMI 25-30) and put them on an 8-week program. Critically, every single participant was in a 25% calorie deficit and followed a resistance training program.
The participants were randomly split into four groups to compare the effects of protein intake and meal timing:
- High Protein + Time-Restricted Eating (THP): Ate 1.6 grams of protein per kilogram of body weight per day within a restricted eating window.
- Regular Protein + Time-Restricted Eating (TRE): Ate a standard amount of protein within a restricted eating window.
- High Protein Only (HP): Ate 1.6 g/kg of protein per day with no meal timing restrictions.
- Regular Protein Only (Control): Ate a standard amount of protein with no meal timing restrictions.
This setup allowed the scientists to isolate the impact of high protein, TRE, and the combination of both on top of a solid lifting and calorie-controlled plan.
The Results: A Clear Win for High Protein
After eight weeks, the results showed that while all strategies worked for fat loss, some were clearly superior for achieving the ultimate goal: losing fat while keeping (or even gaining) muscle.
Fat Loss Was Universal, But One Group Excelled
Every group successfully lost significant amounts of both subcutaneous fat (the kind just under the skin) and visceral adipose tissue (VAT), the more dangerous fat surrounding your organs. This isn't surprising, as they were all in a calorie deficit and lifting weights.
However, the High Protein + Time-Restricted Eating (THP) group saw the greatest reduction in visceral fat. The data showed a very large effect size (d = -1.867), indicating this combination was particularly effective at targeting this harmful fat.
The Magic of High Protein for Muscle Mass
Here’s the part that should get every lifter's attention. While in a calorie deficit, the two groups consuming high protein (1.6 g/kg/day) didn't just preserve their muscle—they significantly increased their fat-free mass.
This is the holy grail of any cutting phase. The High Protein + TRE group and the High Protein Only group both managed to build muscle while simultaneously losing body fat. This highlights the powerful muscle-sparing (and even muscle-building) effect of a high-protein diet during a deficit.
What About Hunger Hormones?
The researchers also measured leptin (a hormone that signals fullness) and ghrelin (a hormone that signals hunger).
- Leptin: Levels dropped in all groups, which is expected during fat loss. The drop was most significant in the two TRE groups compared to the control group.
- Ghrelin: Interestingly, plasma ghrelin levels remained unchanged across all groups. This is great news, as it suggests that neither the calorie deficit nor the time-restricted eating schedule caused a spike in the primary hunger hormone.
Your Actionable Takeaways
This study provides a practical, evidence-based roadmap for a successful fat loss phase. Here’s how to apply it:
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Make Resistance Training Your Foundation: Every participant in this study lifted weights. This is the non-negotiable signal your body needs to hold onto muscle when calories are low.
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Prioritize High Protein Intake: The standout finding was the power of protein. Aiming for a target like 1.6 grams per kilogram of body weight (or around 0.73 g per pound) was key to increasing fat-free mass in a deficit. If you're cutting, your protein needs go up, not down.
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Consider Time-Restricted Eating (TRE) as a Tool: TRE, a form of intermittent fasting, isn't a magic bullet, but this study shows it can be a powerful tool. When combined with high protein, it led to the greatest reduction in visceral fat. It can also be a simple way to adhere to a calorie deficit without feeling like you're constantly fighting off hunger.
In conclusion, if your goal is to get leaner without losing performance and muscle, the evidence points toward a powerful synergy: lift heavy, eat plenty of protein, and consider structuring your meals within a time-restricted window.
Reference: Bagherpour F, Arazi H, Rajabi H, Campbell BI. (2025). High-Protein Time-Restricted Eating Alongside Resistance Training Reduces Adipose Tissue While Preserving Fat-Free Mass in Women With Overweight: A Randomized Controlled Trial. International journal of sport nutrition and exercise metabolism. https://pubmed.ncbi.nlm.nih.gov/40796095/