Episode 110 – 6 Things We Have Changed Our Minds On

Key Topics Covered

man planning outcomes

Aidan’s 3 Points:  

Muscle Significantly Increases Metabolic Rate 

  • I used to be of the belief that gaining more muscle significantly increased our metabolic rate.
  • This stemmed from working with bodybuilders who were needing and struggling to eat a lot of calories.
  • However research has shown that muscle / lean mass only contributes about 12 kcal per kg and fat mass about 4 kcal per kg to our resting metabolic rate.
  • To put this into perspective, if you gained 10kg of muscle and lost 10kg fat, this would only change your resting metabolic rate by 80kcal per day.
  • There are several reasons potentially explaining why these bodybuilders were requiring such high calories.
    • To achieve these body composition goals, you would probably be training more and/or capable of training more. This would ultimately increase daily energy expenditure.
    • These individuals are also very adherent to hitting a specific calorie target. Ultimately, as they spend a longer time in a calorie surplus, there would also be changes through metabolic adaptations.

A Large Calorie Surplus Is Ideal

  • When I first got into this and looking at forums such as bodybuilding.com, a 500 kcal surplus was suggested as being the gold standard and a good starting point which would lead to about half a kilo per week weight gain.
  • However looking more into the research and thinking about this logically, I have changed my mind on this amount.

Studies and Practical Relevance:

  • In a previous podcast, we explored a study done on college athletes where one group was in a 500 kcal surplus, and other group was instructed to eat ad libitum.
    • The results showed that ad libitum group had a really good rate of muscle gain in comparison to fat gain.
    • Alternatively, those in the 500kcal surplus group, gained significantly more body fat compared to muscle.
  • This suggested to me, that a 500 kcal is probably too large and doesn’t increase muscle growth that much, particularly for those who have been lifting for a while.
  • Additionally, if you were on a 12 month calorie surplus, this would be about 26 kg weight gain.
  • Thinking about this logically, even if you scaled back the time frame, only a very small proportion of this weight gain would come from muscle.
Scales and tape measure

Rate of Weight loss and Rate of Regain

  • I used to be of the assumption that greater rates of weight loss would lead to greater rates of weight regain.
  • However, what seems to occur in both the research and in practice, is that the rate of weight loss does not seem to impact weight of regain.
  • One example was evident in the 800 calorie diabetes study mentioned below, where rates of regain after two years were similar between groups.
  • This meant they were down in weight in comparison to the other group overall.
  • What seems to be more important is what occurs after the weight loss period.

Leah’s 3 Points: 

Everyone Should Eat Breakfast

  • I used to be a big advocate for breakfast being an important start to the day for weight management and weight loss. 
  • If a client came to me and wasn’t a breakfast eater, I would encourage them to add a breakfast meal in.
  • But now after both working with lots of people over the years and also delving more into the research around breakfast and weight management, I would say it really isn’t the big deal I thought it was.
  • Different eating patterns work for different people. Some individuals just don’t like to eat in the morning or prefer to start their food intake around mid-morning or lunch time. 
  • If this is someone’s preference and they don’t have any issues around bingeing or overeating later in the day, then I am not going to push them to have breakfast for no reason.
  • We also recently did a podcast on the impacts of having breakfast VS not having breakfast on caloric intake and we summarized in that episode that most of the research has actually shown an overall greater calorie intake in those who eat breakfast than those who don’t.
  • That is not to say that breakfast is inherently bad for weight management or weight loss and there are many positive reasons to consume breakfast but it just isn’t the big deal, I once thought it was.

1200 Calorie Diets Are Unsuitable for Everyone

  • Being in this space, you often hear the perspective that this amount of calories is irresponsible and will be harmful.
  • However after working with a lot of people, I have realised this actually may is necessary for some individuals.
  • For example, smaller individuals who are fairly sedentary may require this amount for a deficit.
  • Another example that prompted this thinking involved a study in those living with Type II Diabetes.
    • Participants were put on a 800 calorie diet for 12-16 weeks.
    • They lost over 15kg and remission rates were significantly higher than those who were on a slow and steady weight loss protocol.
    • Excluding non medical studies, the results outperformed any other study on diabetes management.
    • This may not have occurred if you followed the principle of never eating under 1200 calories.
Soy and tofu

Soy Has No Effect on Human Hormones

  • The truth is more nuanced.
  • Soy contains phytoestrogens, which is a plant compound that is very similar to oestrogen, the female sex hormone.  
  • These phytoestrogens can actually act like oestrogen in the body but with a much weaker effect.
  • In pre-menopausal women, phytoestrogens can actually have an estrogen-blocking action.
  • On the other hand, in post-menopausal women when oestrogen levels have reduced, phytoestrogens can have the opposite effect.  
  • In post menopausual  women the impact on oestrogen can actually have a beneficial impact of menopausal symptoms such as hot flushes.
  • In severe cases, there have been some feminising effects in men showing decreases in testosterone and increases in oestrogen.
    • It is important to note, that these are outliers and the intake of soy was very high.
  • This may affect people differently due to individuals variations in sensitivity.

Relevant Links / Resources

Studies Mentioned