How a group of unfit women lost 21% body fat and added 15% muscle mass in just 12 weeks

Losing weight and gaining muscle are two of the most common goals among adults looking to get fit. What if both could be done in a healthy, motivational way without taking any drugs or supplements? A new study shows that combining two popular wellness strategies – time-restricted eating and high-intensity functional training – can lead to remarkable improvements in body composition and cardiometabolic health, particularly for women struggling with obesity.

The study, led by researchers Ranya Ameur and Rami Maaloul from the University of Sfax in Tunisia, involved 64 inactive women with obesity who were randomly assigned to one of three groups: time-restricted eating (TRE), high-intensity functional training (HIFT), or a combination of both (TRE-HIFT). Over the course of 12 weeks, the researchers tracked changes in the participants’ weight, body fat, muscle mass, blood pressure, cholesterol levels, and more.

Fitness regimen not for the faint of heart

So what exactly is time-restricted eating? Simply put, it’s a form of intermittent fasting where you limit your food intake to a specific window of time each day. In this study, participants in the TRE and TRE-HIFT groups were asked to consume all their meals and snacks between 8 a.m. and 4 p.m., fasting for the remaining 16 hours. The beauty of this approach is that there are no strict rules about what or how much to eat during the “eating window” – the focus is purely on timing.

High-intensity functional training, on the other hand, is a type of exercise that combines aerobic and resistance training in short, intense bursts. HIFT workouts typically involve performing a series of functional movements (think squats, lunges, push-ups) at a high intensity for 20-30 seconds, followed by a brief rest period. In this study, participants in the HIFT and TRE-HIFT groups attended three 60-minute HIFT sessions per week.

After 12 weeks, the results were striking. Participants in all three groups saw significant reductions in weight, body fat, and waist circumference. However, those in the TRE-HIFT group experienced the most dramatic changes, losing an average of 12% of their body weight and 21% of their body fat. They also gained an impressive 15% more muscle mass compared to the TRE group.

But the benefits didn’t stop there. The TRE-HIFT group also showed the greatest improvements in cardiometabolic health markers like blood pressure, cholesterol levels, and insulin sensitivity. In fact, their total cholesterol dropped by a whopping 29%, while their “bad” LDL cholesterol plummeted by 48%. These changes suggest a substantially lower risk of developing chronic diseases like heart disease and Type 2 diabetes.

Interestingly, even though the TRE group didn’t exercise, they still experienced significant weight loss and body fat reduction – an average of 10% and 11%, respectively. This finding supports the notion that when it comes to weight management, when you eat may be just as important as what you eat. By limiting their food intake to an 8-hour window, participants likely consumed fewer calories overall without even trying.

TRE-HIFT not just for women

So what makes the TRE-HIFT combination so powerful? The researchers believe it creates a “synergistic effect” where the benefits of each intervention are amplified. During fasting periods, the body shifts from burning sugar to burning fat for fuel. This metabolic switch, coupled with the intense energy demands of HIFT workouts, may accelerate fat loss while preserving or even building muscle mass. Additionally, both fasting and exercise are known to improve insulin sensitivity and reduce inflammation, which could explain the impressive changes in cardiometabolic health markers.

While the study focused on women with obesity, the researchers believe these strategies could benefit a wide range of people looking to improve their health and fitness. However, they caution that fasting and high-intensity exercise may not be suitable for everyone, particularly those with certain medical conditions or a history of disordered eating. As always, it’s best to consult with a healthcare professional before making significant changes to your diet or exercise routine.

As promising as these findings are, it’s important to note that the study had some limitations. The sample size was relatively small, and the intervention period was just 12 weeks. Longer-term studies with more diverse participants are needed to fully understand the potential benefits and risks of combining TRE and HIFT.

Nonetheless, this study provides a compelling case for the power of lifestyle interventions in promoting weight loss and metabolic health. In a world where obesity and chronic disease are on the rise, simple, sustainable strategies like time-restricted eating and high-intensity functional training offer a glimmer of hope.

So if you’re looking to kickstart your health journey, consider giving this dynamic duo a try. With a little discipline and dedication, you may just discover a leaner, stronger, and healthier version of yourself. And the best part? You won’t have to spend hours counting calories or slogging away on the treadmill. Just eat mindfully, move intensely, and let your body do the rest.