Find out what’s an appropriate rate of weight loss for you & how it can impact fat loss.
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Most people judge their success of weight loss by how fast the scale drops. There are many issues with this approach (aggressive dieting, rigidity, adherence, sustainability, long-term success). The focus of this article is the impact your rate of weight loss has on your body.
You lose weight with the intention of losing fat. Not all weight loss is fat loss. The rate in which you lose weight can heavily impact the source of this weight loss (Fat mass or fat free mass). Fat free mass (or Lean body mass, LBM) is the tissues that makes up our bodyweight (Muscle, Bone, Skin, Blood, Organs) excluding fat mass.
The aim of dieting is to maximise fat loss and minimise muscle loss. There’s been numerous studies investigating the effects our rate of weight loss has on strength, fat and muscle loss.
Garthe et al, 2011, compared a slow reduction (SR) of weight loss 0.7% of bodyweight/week vs. 1.4% fast reduction (FR) weight loss approach and studied the effects on lean body mass and strength over a 4 to 12-week period. SR group increased LBM by 2.1% and fat mass loss was 31% whereas the FR group’s LBM didn’t change and their fat loss was 21%. The SR also improved on all strength tests during this trial and FR didn’t with the exception of 1RM squat.
Mero et al 2010, Compared 0.5kg loss/week to 1kg loss/week (-550Kcal/ -1100Kcal respectively) over a 4-week period. This trial ran for 4 weeks, they saw that the 1kg group had ~30% reduction in their testosterone levels and a 5% decrease in bench press strength.
Helms et al 2014 advised that tissue loss during a diet is influenced by the size of the deficit (and therefore rate of weight loss). The faster your rate of weight loss, the more lean body mass you’ll lose. A recommendation of 0.5-1% bodyweight per week has been recommended as a range to optimise muscle retention during dieting, as gradual weight loss rates are superior for muscle retention.
1% of bodyweight has been recommended as the upper limit of rate of weight loss per week and in some sources this has been noted as an aggressive rate of weight loss.
Based on the above research, an appropriate rate of weight loss is 0.5-1% of bodyweight per week to minimise muscle and strength loss. This may not seem like much to most people, i.e an 80kg person losing 0.5% bodyweight per week (~0.4kg / ~0.8lb), but it can be assumed this is predominantly a loss from fat mass.
This gradual approach also enables a lesser deficit, more flexibility, better adherence, consistency and overall sustainability.
Garthe, Ina & Raastad, Truls & Refsnes, Per & Koivisto, Anu & Sundgot-Borgen, Jorunn. (2011). Effect of Two Different Weight-Loss Rates on Body Composition and Strength and Power-Related Performance in Elite Athletes. International journal of sport nutrition and exercise metabolism.
Helms, Eric & Aragon, Alan & Fitschen, Peter. (2014). Evidence-based recommendations for natural bodybuilding contest preparation: Nutrition and supplementation. Journal of the International Society of Sports Nutrition.
Mero, Antti & Huovinen, Heikki & Matintupa, Olle & Hulmi, Juha & Puurtinen, Risto & Hohtari, Hannele & Karila, Tuomo. (2010). Moderate energy restriction with high protein diet results in healthier outcome in women. Journal of the International Society of Sports Nutrition.