Less Might Be More
More protein, less carbs, no sugar, more carbs, less protein, Mediterranean diet, Atkins diet?! In my thirty-six years I have heard almost every different kind of diet advice imaginable. The one thing that has remained steady is that almost always, what was once “proven” effective is soon replaced by a new magic bullet, sure to make me a size 4 again.
According to a recent article on Time.com, It’s Time to Rethink High-Protein Diets for Weight-loss, new evidence suggests “while the diet (high protein) may help people slim down, it doesn’t necessarily improve other health problems under the hood.” Wait, so should I re-think it or will it help me slim down? Rethink protein for weigh loss – they just said it will help slim down! Like most weight loss articles and advice out there, this one is no exception and may add to the confusion.
So, what is the scientific premise of this article? The author cites a small study out of Washington University School of Medicine in St. Louis. The original study, titled High-Protein Intake during Weight Loss Therapy Eliminates the Weight-Loss-Induced Improvement in Insulin Action in Obese Postmenopausal Women, followed 34 postmenopausal women in three conditions: no diet change, calorie-restricted diet (with DRV of protein), and calorie-restricted with increased protein by 150-250 calories. They found that both intervention groups were able to achieve 10% weight loss. Not to shabby! Refer back to the title of the media article and we can stop reading there (weight loss achieved in both conditions, done and done, size 4 here I come!). But, wait, I’m not post menopausal and – oh yeah – they mentioned insulin action. So, this sample is not exactly representative of larger populations.
The popular media article, like the scientific study, goes on to explain that the women who did not increase protein experienced a 25 – 30% improvement in insulin sensitivity, a key risk factor in developing type-2 diabetes. So, surprisingly, the metabolic benefit came to those who didn’t increase protein in their diets. The scientific article also states that the high-protein condition experienced a 45% reduction in the weight-loss-induced decline in lean muscle mass. So, higher protein diets resulted in more muscle retention. The authors concluded that protein content of a weigh loss diet can have profound effects on metabolic function. These two major findings have positive implications that relate to overall health, but applications by health practitioners may differ depending on concerns around type-2 diabetes.
Despite the fact that this was a small study including a very specific demographic, health practitioners can still find some important take-aways. Based on the results of the study, if obesity complications such as type-2 diabetes are a concern, then adopting a weight-loss diet that includes protein in moderation should be more beneficial for the overall health of an individual. However, if muscle mass retention is a concern – as it might be with postmenopausal women, then a high-protein diet helps retain muscle while also losing fat.
Sifferlon, A. (2016, October 11). It’s Time to Rethink High-Protein Diets for Weight Loss.
Retrieved October 17, 2016, from http://time.com/4526448/high-protein-diet-weight- loss-insulin/
Smith, G.I., & Yoshino, J., et al., (2016). High-Protein Intake during Weight Loss Therapy Eliminates the
Weight-Loss-Induced Improvement in Insulin Action in Obese Postmenopausal Woman. Journal of
Applied Developmental Psychology, 17(3), 849-861. http://dx.doi.org/10.1016/j.celrep.2016.09.047
I found this study very interesting. I’m more so intrigued by the study population. Washington University Medical School studied only 34 individuals. The criteria for this study was very narrow, “Insulin Action in Obese Postmenopausal Women” were the 34 participants. So not only did you have to be an older woman who already went through menopause, but you had to be obese and be susceptible to diabetes. Me, as a 23 year old female, who by the worlds standard is not obese, but wouldn’t hate to shed a few pounds looks at this study and would love to have data to look at that pertains more to my lifestyle. What would the results of “no diet change, calorie-restricted diet (with DRV of protein), and calorie-restricted with increased protein by 150-250 calories” be if more of a younger population did this study? I’m curious if Washington University Medical School would go back and edit this study so that it would have more wider results.
I found this very interesting. I once met with a nutritionist (almost 10 years ago) and one of the first restrictions was not to eat after 6 pm. Her rationale was that those calories would not get burnt off from daily activity. That advice, right or wrong, stuck with me. I always try to have dinner on the table by 5:30 and avoid “snacking” in the evening. This study seems like it may be underpowered a bit with only 29 participants but does bring up important considerations for weight loss. It is interesting, but makes sense that they gained the weight back (and possibly even more weight) after the restrictions were lifted. If they didn’t replace the calories that they were forgoing in the evening during the day and then reintroduced those calories this seems very logical.
A separate Women’s Health article talked about the relation to night time eating and reduced melatonin (a sleep hormone) and leptin (a satiety hormone) production. The take-away being that your brain isn’t getting the message that you are tired and full. With links between sleep quality and weight gain this is another consideration for curbing nighttime trips to the pantry.
So, here’s the thing: high protein diets tend to result in weight loss due to the high-satiating effect of the protein. What I am curious of, after reading this article, is, how much weight did each group actually lose and what level of lean muscle mass reduction the calorie restricted group experienced? Also, 150-250 calories of extra protein is not a lot, roughly 1 cup of chicken breast. Increases in insulin sensitivity are typically seen after only a 5% reduction in weight in obese patients. Did the authors conclude that the high-protein group got no benefit at all from their diet despite losing double the “typical” percentage to see effects?
This article was incredibly relevant though, as post-menopausal women are a very large group that seeks weight loss advice. So if I were to have two post-menopausal clients, a diabetic and a non-diabetic, now I know what kind of weight loss suggestions to make.
Wow!! I love this comment so much. Muscle loss in this age group is so extremely important because age related bone loss is pertinent in post-menopausal woman and muscle mass helps to prevent this. Preservation of lean mass with higher protein diets is pretty consistent across the literature though, so I wasn’t surprised at all with these findings. The way it was presented made it sound paramount. Per usual, the sensationalized nature of the article was over-enthusiastic considering the extremely small sample size. I want to see their power calculation because 27 people split into *three* groups is an extremely small sample size (27 people completed the study).