Weight Loss: A (Not So) Simple Balance (Q&A)

• May 22, 2015

Dear Roddy, I am following your BodyWHealth advice, especially Golden Rules #1 (10,000 steps 5 days per week) and #2 (count calories). I’m feeling good, but am frustrated that I’m not losing weight as quickly as I would like. Please advise. PQ

Dear PQ,

Thank you for your question, and congratulations on pursuing BodyWHealth. You’re doing a great job by exercising and counting calories. Even if you’re not losing weight as quickly as you want, you’re still improving your health, for sure!

Here is a description of the human energy equation, an explanation for the variability in weight loss responses we see between individuals, and a couple of suggestions for you to consider.

For the purposes of simplicity, we have a simple equation at work in our bodies that relates our energy intake to our energy consumption. When our intake is bigger than our consumption, we store energy as fat, and gain weight. When our intake is smaller than our consumption we burn off energy stores (mainly in the form of fat, in healthy individuals) and lose weight.

Energy intake is simple; this comes from our food.

Energy consumption comes from three different processes. The first is the basic energy of living, known as Basal Metabolic Rate (BMR). This is the energy that goes to driving our liver, heart, brain and all the other organs and tissues that keep us alive. Regardless of our activity levels, this metabolic activity consumes energy (even while you sleep). For most of us, it accounts for the majority of energy consumed in any one day. Our BMR is largely dependent on our size, although there is some variability between individuals of the same size. We all know those lucky individuals that seem to be able to eat anything without gaining weight! BMR starts extremely high as we grow from babies into adults, and continues to decline through life (with a decrease of about 20% from the age of 20 to the age of 70). This accounts for the tendency to put on weight more easily as we grow older.

Then we have the Energy Consumption of Activity. This is the energy we burn to exercise. It is voluntary energy expenditure and goes up or down depending on our daily activities.

Finally, a tiny amount of energy is allocated for the digestion of our food. We count this separately from our BMR, because it depends on the nature and size of the meal. If we don’t eat, then there is no energy required for digestion. On the other hand, a huge meal requires more energy for digestion. This is known as the Thermic Effect of Food.

The simple balance, and weight gain and loss are captured in the diagram below.

When somebody needs to lose weight, we advocate for a negative calorie balance of between 500 and 1000 calories per day. This means that their total consumption must be higher than their intake by between 500 to 1000 calories per day. Reducing their intake by 250 calories per day (that’s a bar of chocolate like a Snickers or Twix, or a small serving of MacDonalds fries), AND increasing their exercise consumption by 250 calories per day (that’s a 30 minute bike ride or a moderate-paced walk of about 45 minutes for an average sized woman), they will reach this target. They will lose 3500 calories per week, which is roughly equivalent to 1 pound of fat per week.

The problem with this simple math is that there can be considerable variability between individuals in their response to calorie restriction and to exercise. So, you and your friend who weigh the same, eat the same and exercise the same may end up losing weight at different rates. The reason for this is that the body sometimes compensates for the reduction in energy intake, and/or the increase in energy consumption. The body tries to protect itself by conserving energy either by modifying your appetite or your BMR, or both.

A recent study published described two different metabolic responses to calorie restriction; a “thrifty phenotype” in which the body reduces its energy requirement (BMR) to protect itself against energy deficiency, and a “spendthrift” metabolism that loses weight more rapidly.

Another study described how some bodies reduce their energy expenditure (by reducing BMR) to protect against an increase in the energy demand of exercise.

What is my advice for slow weight losers?

1. The problem is that we’re not very smart yet at determining how your body will respond. Your best guide is your own experience. Close awareness of your calorie balance and your body’s response will help you to manage your weight appropriately. Hence Golden Rule #2!

2. If you want to lose weight, increase your exercise and reduce your calorie intake. If you only do one, for example reduce your calorie intake by the full 500 calories per day, you may be more likely to induce a protective response by your body.

3. You don’t want to hear this, but try reducing your calorie deficit a bit. So, aim for a negative balance of only 250 calories per day. See how this works. It may be that less extreme energy deprivation results in a less rigorous compensatory response.

4. Don’t focus on your weight, but how you feel. I don’t like the bathroom scale. You should have a vague idea of your actual weight and your goal, but don’t obsess over this. It is far more important how you feel about yourself. Most of us care more about how we look and feel and how our clothes fit us.

5. Be patient! It’s fantastic that you are losing weight. Check your equations, and make sure that your calculations are correct. Then hunker down for the long haul. You’re doing great things for your health, even if your weight is taking a while to respond. And when you reach your goal, you’re far more likely to maintain it, in part because of the fantastic diligence that has got you there!

Have fun,

Roddy

If you have a question, please submit it via the connect tab. I try to answer all questions, either by direct email response, or by posting for all to see. I will not publish your name in public responses. Remember, there is no stupid question!!