Network Magazine Autumn 2019 | Page 21

3. Physical activity (PA) You’re a fitness professional, so you know this, but we’ll recap anyway. Physical activity is the calories you burn from purposeful movement, such as walking, running, working out at the gym, gardening and riding a bike. Obviously, how much energy you expend through physical activity will change depending on how much you intentionally move around. 4. Non-exercise activity thermogenesis (NEAT) Non-exercise activity thermogenesis (NEAT) is the calories you burn through fidgeting, staying upright, and all other physical activities except purposeful exercise. This, too, varies from person to person and day to day. Considering all of these factors, this part of the equation should more accurately be: Energy out = RMR + TEE + PA + NEAT Each of these is highly variable. Which means the ‘energy out’ side of the equation may be just as hard to pin down as the ‘energy in’ side. tries to keep your weight steady when you take in less energy and start to lose weight: • Thermic effect of eating goes down because you’re eating less. • Resting metabolic rate goes down because you weigh less. • Calories burned through physical activity go down since you weigh less. • Non-exercise activity thermogenesis goes down as you eat less. • Calories not absorbed goes down and you absorb more of what you eat. It’s important to note that if you have lots of body fat to lose, many of these adaptations don’t happen right away or are very modest initially. As you become leaner, however, this adaptive thermogenesis really ramps up. Reducing calorie consumption can lead to a much lower rate of weight loss than might be expected, and can even lead to weight re-gain Calorie cutting counterproductive? In addition to these tangible effects on the equation, reducing actual calories eaten Revising the equation... So, while the Energy Balance Equation sounds simple in principle, all these variables make it hard to know or control exactly how much energy you’re taking in, absorbing, burning, and storing. So, revisiting that ‘simple’ Energy Balance Equation, we can see that, actually: Changes in bodily tissues = [actual calories eaten - calories not absorbed] - [RMR + TEE + PA + NEAT] Reducing calorie consumption can lead to a much lower rate of weight loss than might be expected, and can even lead to weight re-gain also causes hunger signals to increase, causing us to crave (and maybe eat) more. The net effect leads to a much lower rate of weight loss than might be expected – and in some cases, could even lead to weight re-gain. Setting better expectations The calorie-cutting effect is just one example of the amazing and robust response to trying to manipulate one variable. There are similar responses when trying to manipulate each of the other variables in the equation. The point is, metabolism is much more complicated, and interdependent, than most people realise. Therefore, trying ‘what used to work’ for you, or relying on calorie counting, often won’t get you the results you want. As your energy balance evolves, so must your strategies for losing fat or maintaining your weight. Understanding energy balance means setting better expectations about body change. Losing weight, and keeping it off, is accompanied by adaptive metabolic, neuroendocrine, autonomic, and other changes. It’s also important to remember that how your metabolism reacts to changes in energy balance will be unique to you. How much you can lose or gain will depend on your age, your genetic makeup, your biological sex, if you’ve had relatively more or less body fat and for how long, what medications you’re taking, the makeup of your microbiome… and probably a whole lot of factors we don’t even know about yet. Knock-on effects of variables Even if all the variables in the final equation above were static, the Energy Balance   Equation would be complicated enough. But things get crazy when you consider that altering any one of the variables causes adjustments in other, seemingly unrelated variables. This is a good thing, of course. Our human metabolisms evolved to keep us alive and functioning when food was scarce. One consequence is that when ‘energy in’ goes down, ‘energy out’ goes down to match it, because we burn fewer calories in response to eating less. Likewise, when ‘energy in’ goes up, ‘energy out’ tends to go up too, because we burn more calories in response to eating more. This isn’t the case for everybody, and it doesn’t work ‘perfectly’, but generally, that’s how it goes and how our bodies avoid unwanted weight loss and starvation. It’s how humans have survived for two million years. The body fights to maintain homeostasis. To illustrate this point, here’s how your body Brian St. Pierre, MS, RD, CSCS Brian is a US-based registered dietitian (RN), certified sports nutritionist (CISSN) and certified strength and conditioning specialist (CSCS). He spent three years as the Head Sports Nutritionist and as a Strength and Conditioning Coach at Cressey Sports Performance and is a nutrition coach with Precision Nutrition. precisionnutrition.com 12 – 14 APRIL 2019 / ICC, SYDNEY THE FITNESS INDUSTRY’S BIGGEST WEEKEND IS BACK AND NETWORK MEMBERS SAVE! Brian’s coming to Oz to share his insights at FILEX. Join him for: • • • • • Fat Loss: The Strategies That Really Work Human Metabolism & The Calorie Conundrum Calories, Macros, Portions – How To Best Track Intake Fundamental Principles of Performance Nutrition Meal Plans That Don’t Suck Go to FILEX.com.au to check out the full program, featuring sessions on everything from PT and Business, to Group Fitness and Nutrition. Network Members get the best available prices: simply register for the Member Rate using your Network Membership number. NETWORK AUTUMN 2019 | 21