| This documentary is based on an 8-week study conducted by Stanford University that put 22 sets of genetically identical twins on opposing (but healthy) diets: ominvore and vegan. Twins were chosen as the study population to try to limit genetic and epigentic influences on dietary intervention outcomes. The subjects were given their meals for the first four weeks and had to prepare their own meals during the second 4 weeks. The primary goal of the study was to see if following a vegan or an omnivorous diet (both favored whole/unprocessed foods and severely limited ultra processed foods and added sugars to be as comparable as possible) would change cardiometabolic profiles. Specifically, “The primary outcome was difference in low-density lipoprotein cholesterol concentration from baseline to end point (week 8). Secondary outcome measures were changes in cardiometabolic factors (plasma lipids, glucose, and insulin levels and serum trimethylamine N-oxide level), plasma vitamin B12 level, and body weight.”
When you read the results, both in the abstract and in the press, it appears that those on the vegan diet significantly improved their profiles and lost weight. Hold that thought. I know that the study authors are biased towards plant-based diets, and like The Game Changer, there is/was an agenda to the NetFlix doco; to push the plant based ethos. First, we know that when anyone increases the total intake of fruit and vegetables, eliminates as much processed foods and added sugars as possible there will be a significant improvement in cardiometabolic profiles, and the extent to which a vegan vs omnivore diet can influence this was the major goal of the study; and yes, it does appear that the vegan diet improved (lowered) LDL-C and improved resting glucose levels significantly moreso than the omnivorous diet. There is also statistical evidence to show that the vegan group lost more weight than the omnivorous group. BUT what is not shown in the journal article, and should be, is that the weight loss was primarily lean mass, with a higher percentage of lean mass loss from the vegan group (as shown by DEXA results)!
When we dig into the methods and results, we see that the diets were not matched for protein, with a negative change in % distribution in the vegan group, and an increase in the total intake (grams) and % distribution in the omnivorous group. Additionally, (as shown in the doco and the supplementary materials), the two twin groups who lost the most lean mass, were not eating enough for their activity level. One twin group were 22-y old men following the resistance training program they were given in the study, which may have been more intensive than the self-made plan they were following, and another twin group were 55-y old Filipino women who felt too full on the diets and also felt they needed to do more cardio on-top of the resistance training program prescribed.
Although this is a well-done study, and published in JAMA, it is sad to see that the whole picture is not represented, especially when it comes to lean mass. Lean mass is so important for health and very difficult to build, especially with age. I wish the media and study authors would be a bit more transparent in their interpretations, to really push home the actual results- increasing fruit, vege, whole grains and lean protein improve overall health. It is not the vegan diet, per se, but the overall clean up from the typical S.A.D. diet; and if there is not enough calories coming in to support the body, it does not matter what diet you follow, lean mass is one of the first tissues to be lost.
What is the most common question I have been asked over the last few weeks?
The MOST common question I get, across the board, is something similar to this:
“I’m a 50+ year old peri/post-menopausal woman and I am doing all the things (LHS, S.I.T., H.I.I.T, more plants and protein in my diet), but I am extremely frustrated with ever increasing body fat. I’m an endurance athlete. I am not a tracker but in my frustration, I have been closely tracking my calories and protein intake; at 142 lbs and 5-something feet tall, I am getting around 110 g of protein per day. I have recently been adding 2-3 sets of interval training to my workouts in addition to lifting every other day. Today I compared my body comp results from a month ago. My weight is down but my body fat went up nearly 3%! It appears that I lost muscle rather than gained it! My calorie goal is about 1400-1600. I am on estrogen and progesterone. Can you please help?”
First and foremost, there are not enough calories coming in to support an active woman, regardless of age or hormonal status! Nor is there enough protein! Low carbohydrate availability and low energy availability is a significant and real problem, and so many women are falling into it. As I noted above in my notes on the Netflix doco, eating enough calories and enough protein is one of the only ways to preserve your hard-earned lean mass. Using MHT will slow the rate of loss from natural aging, but it will not counter lean mass loss and body fat gain from inadequate fueling. Please, I want everyone to shout it out now- Eat! EAT PLENTY and FUEL! Food is GOOD and we need it to keep our lovely lean mass!
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Remember, you are an athlete if you train on purpose. |
