Metabolism and dieting: If you’re Not assessing you’re guessing

The Christmas binge season has been and gone, we are now in the territory of what is informally referred to as the annual tradition of starving oneself as a penance for your syns (I know it's sins, I just borrowed a slumming world term). Metabolism is key part of both my private work and research, and it never ceases to amaze me how misunderstood the topic is.

I thought we’d look over an old article from the Daily Mirror. Not exactly PubMed but it is where most people will go for “expert opinion” once New Years Eve has passed. The article by Tanith Carey was titled “How many calories do you REALLY need to eat every day? We put six women to the test.” (1) In the article they want you to consider why some women can eat anything and not gain weight, whilst others gain weight just by looking at a piece of cake. Now that simply isn’t true, everyone has the potential to gain weight, our ability to survive thus far is most likely due to our ability to down-regulate our metabolism and store energy in order to survive periods of famine. (2, 3)

The article goes on to mention the dreaded NHS guidelines that the average female needs 2,000 calories a day. The problem is how we define average female. Scientifically we know that we are individuals, and to use the term “average” is beyond useless, indeed, the attempts to find Norma, a standard woman in the 60’s proved fruitless. And given the apparent society wide problem with obesity, trying to follow some dictated policy, both is not working and also shows an utter disregard for your individuality. With the scientific tools we have at our disposal we no longer need to conform ourselves to the system, we can define our own needs.

The article does touch on the number of calories “we can eat” varying from woman to woman. They then went onto measure oxygen inhalation and carbon dioxide exhalation to enable the calculation of resting metabolism in six “individuals. Dr Naufahu stated “As we get older, our metabolism tends to slow down, so unless we keep up our muscle mass with exercise, those extra calories get stored as fat, which is why so many middle-aged women battle with their weight.” Personally it leaves me astonished that no mention is made of food sustaining the metabolism, I've completed enough study over the years to conclude that you'll struggle to maintain or increase muscle mass without adequote food. As you'll see, metabolism seems to suffer most at the hands of the lieflong dieter.

One of those tested was a personal drainer called Jo who was 53 at time of publication, and needed 1,600 calories despite eating 1,942. Her various admissions; 

“For most of my life I’ve yo-yo dieted.….In my teens, I lost the weight through dangerous crash dieting. But then I married and gained more pounds with each of my pregnancies until I went up to 15st….”

“I started exercising and eating no more than 1,200 calories a day. It took 22 months for me to lose five stone….”

“Now I’m happy with my body and keep my figure trim with exercise and eating healthily during the week – fruit, protein and salad but indulging at the weekends. I am particularly partial to red wine…..”

“The weight still comes off much more slowly than it used to in my younger days.”

This really sums up the metabolic adaption created by dieting or making incorrect assumptions about what your body needs in terms of its energy requirements.


Further into the article Dr Naufahu’s makes a childish error when she states that "To lose a pound of fat, you need a calorie deficit of 3,500-kcals each week.” She then states that Miss Average needs to cut down by 400 to 500 kcals a day. Yet the belief that a 3,500-kcal deficit will result in one pound of weight loss (about 0.45 kg) is misguided if not corrupt. It continues to be cited in “over 35 000 weight loss educational websites” plus copious amounts of academic textbooks, scientific articles and so called experts in diet and nutrition. (4) Even the British Dietetics Association pushes the totally unreferenced 3500-kcal rule. (5) Even if it was factual it fails to account for the metabolic adaption caused by dieting. To put it simply, the greater the degree of energy restriction to encounter, the more efficient you become as energy output is slowed to protect you. (6)

Then we meet Nicola who is 54 and eats 1,800 calories despite her RMR being 1,497, interestingly she claims to .

“eat more than half what I used to in my 30s and find it harder and harder to keep it off, especially since I turned 50."

“I had a hysterectomy at 42 and have been on HRT ever since. I think that keeps me heavier because it makes me suffer water retention."

“It’s very frustrating because I don’t eat a lot. I start the day with an omelette and have lots of fish and salads – with the odd cereal bar thrown in as a treat.”

So we can see the daily recommendation based on the “average woman” are pretty much worthless, and that random dieting seems to have often detrimental effects on the Resting Metabolic Rate (RMR). The next stage up from this guesswork would be predictive equations such as Mifflin-St Jeor, (7) which I used during my MSc dissertation due to the costs involved in utilising more accurate methods across a large study group.

There can be no doubting that predictive formula provides a greater degree of individual understanding when developing and evaluating a nutrition plan, yet predictive equations may effect longterm outcome due errors in accuracy.(8, 9) Oshima et al, (10) concluded that indirect calorimetry was an important tool for nutritional therapy of patients, so it would seem logical to conclude that those looking to lose weight (often for health reasons) should utilise the best possible tools available to enable both long term success and evade future health problems. 

That studies such as Fothergill et al, (11) describe poor weight-loss maintenance at 6 year follow up, coupled with RMR suppression, indicates the importance of knowing individual RMR in order to maintain health and longevity whilst attempting to attain weight-loss goals. (12) Whilst costs may seem prohibitive it must be noted that during a study funded by Weight-Watchers, 5 year weight-loss maintenance was reported as 16.2 percent. Whilst this seems to make it plausible it must be considered that by the studies own admission the participants were made up of only the most successful members, and is no indication of actual success rates amongst all all members. It is also worth pointing out that the study was looking at “success” measured in terms of members who managed to maintain 5 percent of their weight-loss over 1, 2 and 5 year periods. Ask yourself would you really be happy being one of the 16.2 percent in an elite group that after 5 years had managed to maintain only 5 percent of your weight-loss? Thought not.

So, at the cheapest rate for online access you’d be paying £122.68 for a year, right through to £325 a year to attend group meeting.(13) Cheap enough to risk it for those unaware of their chance of “success” and a great business model for repeat customers tricked into thinking their outcome was due to poor willpower.

So how would I tackle the issue of weight loss?

Firstly you need to know your own energy requirements, not those of Miss Average. 

Option 1. Select a formula, work out your RMR and add on your activity to give you a better estimation of your needs.

Option 2. Book in for a RMR test and gain a more accurate picture of your needs.

After completing option 2 I would then suggest (or I do it for you if you visit me) that you complete option 1 to see how your actual RMR compares against what standardised formula suggests you need.

Next you need to consider the fact that after most RMR tests are completed the individual is then subjected to the 3,500 calorie deficit rule. We already know this isn’t backed up by evidence, and cannot work long-term due to metabolic adaption. So my suggestion would be to eat the amount your body needs and begin to restore your youthful metabolism. If you are supplying the correct amount of energy you will benefit from not needing extreme willpower, and over time you’ll see the RMR begin to raise as the metabolism adapts in response to the consistent supply of energy.

Any questions, leave a comment.

References:

1. Carey, T. (2013). How many calories do you REALLY need to eat every day? We put six women to the test. 
http://www.mirror.co.uk/lifestyle/health/how-many-calories-you-really-2161639 published 14 Aug 2013 and updated 27 Jun 2016

2. Galgani, J., & Ravussin, E. (2008). Energy metabolism, fuel selection and body weight regulation. International Journal of Obesity (2005), 32(Suppl 7), S109–S119. http://doi.org/10.1038/ijo.2008.246

3. Mattes, R, D., Pierce, C, B., and Friedman, M, I. (1988). Daily caloric intake of normal-weight adults: response to changes in dietary energy density of a luncheon meal. Am J Clin Nutr, 48(2):214-9.

4. Thomas, D, M., Martin, C, K,. Lettieri, S., Bredlau, C., Kaiser, K., Church, T., Bouchard, C., and Heymsfield, S, B. (2013). Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? Commentary on a commonly accepted rule. International Journal of Obesity (2013) 37, 1611–1613; doi:10.1038/ijo.2013.51; published online 30 April 2013.

5. BDA Food Facts Sheet https://www.bda.uk.com/foodfacts/Want2LoseWeight.pdf accessed 20th December 2016.

6. Luke, A., and Schoeller, D, D. (1992). Basal metabolic rate, fat-free mass, and body cell mass during energy restriction Metabolism - Clinical and Experimental , Volume 41 , Issue 4 , 450 - 4566. 
7. Mifflin, M, D., St-Jeor, S, T., Hill, L, A., Scott, B, J., Daugherty, S, A., and Koh, Y, O. (2005). A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990 Feb;51(2):241-7.

8. Frankenfield D., Roth-Yousey, L., & Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005 May;105(5):775-89.

9. Aliasgharzadeh, S., Mahdavi, R., Asghari Jafarabadi, M., & Namazi, N. Comparison of Indirect Calorimetry and Predictive Equations in Estimating Resting Metabolic Rate in Underweight Females. Iran J Public Health, Vol. 44, No.6, Jun 2015, pp.822-829

10. Oshima, T., Berger, M, M., De Waele, E., Guttormsen, A, B., Heidegger, C, P., Hiesmayr, M., Singer, P., Wernerman, J., & Pichard, C. (2016). Indirect calorimetry in nutritional therapy. A position paper by the ICALIC study group. Clin Nutr. 2016 Jun 22. pii: S0261-5614(16)30142-X. doi: 10.1016/j.clnu.2016.06.010. [Epub ahead of print]

11. Fothergill, E., Guo, J., Howard, L., Kerns, J. C., Knuth, N. D., Brychta, R., Chen, K. Y., Skarulis, M. C., Walter, M., Walter, P. J. and Hall, K. D. (2016), Persistent metabolic adaptation 6 years after “The Biggest Loser” competition. Obesity, 24: 1612–1619. doi:10.1002/oby.21538 

12. Rizzo, M, R., Mari, D., Barbieri, M., Ragno, E., Grella, R., Provenzano, R., Villa, I., Esposito, K., Giugliano, D., & Paolisso, G. (2005). Resting Metabolic Rate and Respiratory Quotient in Human Longevity. The Journal of Clinical Endocrinology & Metabolism 2005 90:1, 409-413

13. Weight Watchers Pricing structure. Accessed 20th December 2016 https://www.weightwatchers.com/uk/weight-loss-plans?