Traditional wisdom states that “slow and steady wins the race,” and while that may have helped the tortoise beat the hare, the slow and steady approach is often under scrutiny when it comes to weight loss.
Sure, slow and steady is thought to be the most sustainable approach for those attempting to lose weight, but is it the most effective according to research?
Today, we’ll discuss which is better for long-term weight loss success -- fast or slow.
What is “Slow” Weight Loss?
Typically, “slow” weight loss is categorized as losing between 0.1-1 pound per week.
“Fast” weight loss would be a weekly weight loss exceeding 2 pounds.
Which is More Effective? Slow or Fast Weight Loss
Let’s first begin to answer this question by stating some fundamental principles of weight loss.
Namely, in order to lose weight, you must consume fewer calories than you burn in a day. This places your body in a negative energy balance whereby the body is forced to rely on its own energy stores (body fat) to fulfill its energy needs that aren’t being met by food intake.
Do this long enough, and you will lose weight.
Now, to make weight loss more meaningful and effective, there are a few other things you can do, such as consume enough daily dietary protein and perform resistance training several times a week.
Both of these things help retain lean muscle while dieting and encourage the body to lose fat instead of losing a mixture of fat and muscle (which is what it would do if you simply slashed calories and didn’t consume enough protein or lift weights).
The next question individuals are faced with is how big of a calorie deficit should they aim for as the magnitude of the deficit will stipulate whether your weight loss is “fast” or “slow.”
The larger your calorie deficit, the faster you will lose weight (to a point).
If you adopt too large of a calorie deficit, you run the risk of breaking down muscle tissue, stunting metabolism, and abandoning your diet altogether because it’s too aggressive and unsustainable.
Still, the reason many individuals opt for the fast approach is that it shows bigger reductions in weight loss quicker.
This can be incredibly motivating for individuals, especially for those who have struggled with their body weight for a long time.
Seeing the pounds fly off week after week can reinforce that they’re on the right track and fuel their fire to keep going.
However, the dual-edged sword of fast weight loss is that individuals may be more susceptible to burnout as the body and mind can only stand being in a deficit for so long, and when coupled with an aggressive exercise program, it can make it all the more likely an individual will tap out at some point or another.
Another thing to consider (as we mentioned above) is that the “faster” you try to force weight loss the greater risk you place yourself for muscle loss.
Research indicates that you can use between a 20-25% calorie deficit and not risk muscle loss.[1,2,3]
In other words, you can eat between 75-80% of your total daily energy expenditure (TDEE).
One benefit of adopting the fast weight loss approach (if you can stick it out) is that you get it over and done with more quickly, and can then return to maintenance or transition to a calorie surplus to promote muscle and strength improvements more efficiently.
Now, for those in favor of the slower approach to weight loss, the main thrust of their argument is that many individuals find it easier to stick to a smaller calorie deficit and/or less demanding training regimen of cardio and resistance training over time.
Slower fat loss also is less likely to result in muscle loss compared to fast fat loss regimens.
The catch is that you’ll be dieting longer, which may or may not live with your levels of patience and persistence.
So, What’s the Answer? Slow or Fast Weight Loss
Suffice it to say that both options have their pros and cons.
To further complicate matters is that research shows that both slow and fast approaches to weight loss yield similar results.[4,5]
Specifically, researchers found that both fast and slow weight loss leads to reductions in:
- Waist circumference
- Hip circumference
- Body fat mass
There is a slight edge to slow weight loss for lean mass retention, but those trials are confounded by individuals not consuming enough protein and/or adopting a deficit greater than 25% of TDEE.
Additionally, both fast and slow weight loss protocols are effective for improving various metabolic markers, such as lipid and glycemic profiles.
At the end of the day, the decision to take the slow or fast approach to weight loss is a highly individualistic one.
Simply put, some people will want to take a more aggressive approach (even if it may require more exercise and fewer calories) while others will want a slower, more gradual approach.
Realize that you are not locked into one approach forever.
If you decide to try the fast approach and realize you may have bit off more than you can chew, you can always scale back the intensity of your diet and add a few more calories back into your diet and vice versa.
If you start with the slow approach and then realize you have the mental fortitude and willpower to “embrace the suck” of hardcore dieting and exercising, then feel free to give it a go.
After a dieting cycle or two, you’ll understand what works best for your lifestyle and fitness goals.
The only “rule” that you must remember when it comes to weight loss is that you must be in a calorie deficit. How large or aggressive you choose to make it is mostly a matter of personal preference.
- Helms, E.R., Aragon, A.A. & Fitschen, P.J. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr11, 20 (2014). https://doi.org/10.1186/1550-2783-11-20
- Huovinen HT, Hulmi JJ, Isolehto J, et al. Body composition and power performance improved after weight reduction in male athletes without hampering hormonal balance. J Strength Cond Res. 2015;29(1):29-36. doi:10.1519/JSC.0000000000000619
- Redman LM, Heilbronn LK, Martin CK, et al. Metabolic and behavioral compensations in response to caloric restriction: implications for the maintenance of weight loss. PLoS One. 2009;4(2):e4377. doi:10.1371/journal.pone.0004377
- Ashtary-Larky D, Ghanavati M, Lamuchi-Deli N, et al. Rapid Weight Loss vs. Slow Weight Loss: Which is More Effective on Body Composition and Metabolic Risk Factors?. Int J Endocrinol Metab. 2017;15(3):e13249. Published 2017 May 17. doi:10.5812/ijem.13249
- Jennifer L. Kuk, Rebecca A. G. Christensen, Sean Wharton. Absolute Weight Loss, and Not Weight Loss Rate, Is Associated with Better Improvements in Metabolic Health. Journal of Obesity, 2019; 2019: 1 DOI: 10.1155/2019/3609642