Friday Tidbits #11: Eat Less & Move More Still Works
Welcome to Friday Tidbits. This is a very short email with morsels of information to help you tweak your life and health for optimum longevity and healthy ageing.
16 February 2024
Eat Less & Move More still works
This age-old advice to lose weight has been the fall back of doctors and dietitians for as long as weight loss has been a desired outcome (for some at least). It is easier said than done. Eating less takes considerable willpower, planning and most of all long-term consistency.
I want to focus on the Move More bit today.
Accidental experiment #1
A few weeks ago, a friend of mine, mentioned that she is waking in the early hours of the night. She was wondering if it could be hydration related since it had been very hot. And yes, it can be. But what I think was more likely is that she was hypocaloric – she was not eating enough. She recently started a new job as a cleaner and de-clutter consultant (great person to know!). This meant that she was constantly on her feet and moving for many hours more than she was used to. She was not “exercising” more. Her heart rate was seldom above 65% of her max. She was not breathing harder, she was not experiencing muscle strain or soreness. Except for her feet perhaps.
She was suddenly MOVING ALL DAY LONG. And her jeans are feeling a bit loser!
Accidental experiment #2
The last 4 weeks we have moved house. This meant endless packing, lifting boxes, carrying stuff and cleaning. At no point did I feel tired in the same way that exercise would make me feel. The actual week of moving was a bit hectic. I was moving all day and not drinking enough water. (I paid the price for this by waking up screaming one morning with cramps in my inner thigh – not fun.) I was also eating less - there were no snacks in my empty house! The scale showed a loss in weight of 3kg in 2 weeks (happy days). I was not too excited because much of this is due to dehydration and loss of glycogen. I expected the number to go back up after correcting my hydration and restoring my glycogen * levels. It did not. This means that I actually lost fat mass.
* Glycogen is the way we store glucose in the liver and muscle. With every 1g of glucose we also store 2g of water (approximately). When we exercise for many hours or fast or suddenly eat low carb, we can lower our glycogen stores and pee out the water.
When Move More doesn’t work
You will hear many, many people say it doesn’t work. They sign up for the gym and go 6/7 days and huff and puff for 45-60 minutes. Calories spent depends on what you do, how hard you work, how long you work for and of course the usual suspects of age, sex, genetics and body size. Trackers will congratulate you on your efforts and display anywhere from 250-800 calories. Certainly, the effort needs to be celebrated (smiley face). Just not with food please. Half a muffin from your local will bring your calorie intake back to balance i.e. no weight loss is going to happen…
Exercise is good for many things: muscle mass, bone density, strength, endurance, balance, happy hormones and much more. However, for the most part, the hour in the gym is not a great strategy for losing weight. Let me explain.
Daily Total Energy Expenditure (TEE)
TEE = BMR + TEF + EAT + NEAT
It will surprise many how little exercise accounts for the calories that we burn every day. For the average person, up to 60-70% of the energy that we burn every day is dedicated to keeping the lights on. This is termed Basal Metabolic Rate (BMR). Your total Lean Body Mass (LBM) has the biggest influence (up to 80%) on your total BMR1. The review by von Loeffelholz & Birkenfeld (2022) has an excellent and easy to read break down of TEE.
Not much can be done about the total bone mass, but we can increase and should make efforts to sustain, our skeletal muscle mass. BMR as a proportion of TEE is higher in sedentary people.
Many online calculators can help you determine your BMR – try this one. There are several assumptions and calculations that form the basis for these calculators. Be mindful that the number can be incorrect by 5-20%.
Around 8-15% of energy is spent digesting, absorbing, and storing the food we eat. Breaking chemical bonds of molecules requires energy and heat is generated as a by-product of the reaction. To illustrate, imagine you are trying to pull apart lego blocks. Muscles are the energy input and the popping sound you hear when the blocks come apart, is the energy released. This is called Thermic Effect of Food (TEF).
We can tweak BMR and TEF a tiny bit. Not enough to move the needle and it is considered fixed from an academic standpoint. Some hormonal conditions like hypothyroidism can decrease BMR. It takes more energy to digest protein compared to carbohydrates.
Exercise is of course burns a lot of calories while we exercise and is called Exercise Activity Thermogenesis (EAT). For the typical person who exercises for 60 minutes per day, EAT can account for up to maximum of 15-30% of TEE. In people who exercise for less than two hours per week, EAT would only contribute 2% of TEE, around 100 calories per day.
The role of NEAT
This brings us to Non-Exercise Activity Thermogenesis, or NEAT. NEAT is the energy expended for everything we do that is not sleeping, eating and sport-like exercise (Levine 2002)2. It accounts for the largest share of daily activity-related energy spent – even for those who exercise regularly.
It is spontaneous physical activity. It is the energy spent moving: walking around the office or home, shopping, light gardening, housework and looking after children. No high heart rate, no breathlessness, just constant moving at a low level of intensity. Even the most trivial physical activity can increase total energy expenditure substantially. Levels of NEAT between similar sized people can vary as much as 2000 calories per day.
Many of us have a job where we sit for most of the day. If this is you and you do not regularly exercise, then NEAT likely accounts for up to 10% of total energy spent – roughly 700 calories per day. This increases to 50% or more for very active people. People whose job require them to stand for most of the day, like hairdressers, can have a NEAT of up to 1400 calories per day. People that fidget a lot, have a higher NEAT, up to 800 calories per day. People with physical jobs like agriculture, cleaning and trade have very high NEAT.
Australian data show that men are up to three times more active compared to women across all ages3. This data is old, 1986-1990, however I suspect it is still true today. And we move less as we get older4.
NEAT is the variable of TEE that we can influence most.
So, when you suddenly increase your NEAT, total energy expenditure can increase above your homeostatic level - the energy balance that keeps your weight stable. And if you do this for an extended period and you do not compensate by eating more, you will likely lose weight.
One thing to note is that under conditions of prolonged energy restriction (dieting), NEAT will spontaneously decline. Moving will require effort. Many bodybuilders in severe calorie deficits can testify to this where the mere effort of getting up to change the television channel, or more likely find the remote is too much.
Why not just exercise more?
Yes, this will work. I have experienced this a few times myself when training for an upcoming event. Increasing the time spent exercising beyond your current level can over time lead to weight loss. But here is the problem. It takes many hours of low intensity exercise like running long distances, cycling, rowing or similar. I do not include swimming here because most people do not swim for long enough for it to have an impact. And swimming makes you hungry. You are very likely to eat more than you spent.
Most people do not have 2-3 hours per day to dedicate to exercise. Even fewer has the inclination to do so, even if they have the time.
What can you do?
I do not recommend moving house – the stress is far to high! You do not have to change jobs.
You can deliberately increase your moving time. Park at the far end of the parking lot. Walk around the block every hour or so. You could increase fidgeting, though that might annoy the people around you.
If you are calorie restricting with the goal of losing weight and the scale is not changing, consider walking more. One long walk per day or many shorter walks.
Move More, it works and it may be easier than Eating Less.
References:
von Loeffelholz C, Birkenfeld AL. Non-Exercise Activity Thermogenesis in Human Energy Homeostasis. [Updated 2022 Nov 25]. In: Feingold KR, Anawalt B, Blackman MR, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279077/
Levine JA. Non-exercise activity thermogenesis (NEAT). Best Pract Res Clin Endocrinol Metab. 2002 Dec;16(4):679-702. doi: 10.1053/beem.2002.0227. PMID: 12468415. https://pubmed.ncbi.nlm.nih.gov/12468415/
Caspersen CJ, Merritt RK. Physical activity trends among 26 states, 1986-1990. Med Sci Sports Exerc. 1995 May;27(5):713-20. PMID: 7674876.
Harris AM, Lanningham-Foster LM, McCrady SK, Levine JA. Nonexercise movement in elderly compared with young people. Am J Physiol Endocrinol Metab. 2007 Apr;292(4):E1207-12. doi: 10.1152/ajpendo.00509.2006. PMID: 17401138.