Adam C. Stewart
A recent study shows that jumping into a severe energy deficit was just as effective as a progressive progressive energy deficit for body composition. So, are they equivalent? Well, no. A larger net energy deficit should mean a greater loss of fat mass, but this did not happen.
Note: This article was the cover of MASS Research Review for April 2023 and is a review of a recent article by Vargas-Molina et al. If you want more content like this, subscribe to MASS.
We all want to achieve our goals yesterday, which is why the appeal of the accelerated diet will never disappear and why studies like the one currently reviewed (1) are important. On paper, there is a lot of call for faster weight loss. You spend less time changing your lifestyle and feeling uncomfortable, and you make rapid and visible progress that can be very motivating. Unfortunately, what works on paper doesn’t always work in the real world. As indicated by Dr. Trexler in his review of a meta-analysis comparing slow weight loss rates with faster weight loss rates (2), faster rates when comparing interventions with similar overall weight loss result in a slightly higher proportion of weight loss than lean mass, a slightly higher proportion. Thus, it seems that the fable “The Turtle against the Hare” applies in the context of diets. However, wise readers might say: “This is only the matter if a similar weight loss is achieved – the goal of choosing a faster loss rate is to lose more total weight over the same period.”This is absolutely true; however, the current study suggests that attempts at rapid weight loss do not always lead to a higher overall weight loss than slower diets, even when used over the same period of time. In this review, we will address these results and discuss what happened (and why).
Objective and assumptions
Objective
The authors explained that “the objective of this study was to compare the effects of an 8-week protein-rich dietary intervention SER [severe energy deficit] or PER [progressive energy deficit] accompanied by a simultaneous high-volume exercise program (CT), which was composed of body and strength-related variables in resistance-trained women.”
Hypothesis
The authors hypothesized that “eight weeks of Intervention [progressive energy deficit] would produce a greater reduction in FM [fat mass] while maintaining FFM [Fat-free mass] and strength compared to a [severe energy deficit] due to a better adherence nutritional strategy in resistance-trained women.”
Themes and methods
Topics
Fourteen women with at least two years of exercise experience and no reported performance-enhancing medicine use in the last two years participated in this study. Participants had to be between the ages of 18 and 35, menstruate regularly and were not allowed to exercise outside the study or take ergogenic supplements during the study.
Study design
This randomized study in parallel groups compared changes in body composition and performance over an eight-week period in women who underwent aerobic and resistance exercises simultaneously, divided into two groups: a group with severe energy deficit (n=7) and a group with progressive energy deficit (n=7). All participants in this study were recruited into the same laboratory group after completing a previous eight-week study in which they were prescribed a ketogenic diet of 45 kcal/kg of lean mass per day during Resistance training with the aim of increasing muscle mass (3; reviewed here). The prescribed training was identical in both groups in the present study, the only Variable differing in severity and the pattern of energy restriction.
Peculiarities Of The Diet
In the heavy group, the participants were prescribed a diet of 25 kcal / kg of lean mass per day and were asked to follow it for the full eight weeks. However, the progressive group started with 40 kcal/kg of lean mass per day and reduced this intake by 5 kcal/kg per day every two weeks. Thus, they consumed 40 kcal/kg of lean mass per day during weeks one and two, 35 kcal/kg during weeks three and four, 30 kcal/kg during weeks five and six and 25 kcal/ kg during weeks seven and eight. Individuals in both groups were assigned macronutrient distributions of 2 g/kg of protein, 1 g/kg of fat and the remaining calories from carbohydrates. All participants recorded digital meal diaries using the MyFitnessPal app and received advice from a “sports nutritionist with experience in RT [resistance training]” who helped them manage their diet. (I would add that you have also done this in the last eight weeks since you were recruited in a previous study.)
