Exercise Versus Diet: What’s More Important for Losing Weight?
Being healthy is easy, right? “Eat less, move more.” Easy to say, practicality is one of the most important things when it comes to health and fitness. Recommendations like these are general statements that don’t touch on practicality, so when it comes down to it, which is more important? Diet or exercise?
Yes, we all need to eat healthier foods. Yes, we have to do sports every day. There are endless things we could do to be healthier, such as sitting less, eating more vegetables, eating less processed foods, or drinking less alcohol. But they do not take into account the reality of life: we are all limited by a limited number of resources, such as time, energy, willpower, and money. Recommendations that don’t take this into account can easily make us feel like we’re not meeting our fitness and health goals . To give you an idea of the importance of practicality, consider this recent meta-study (ie Research Study) published in the Journal of the American Medical Association , which attempted to find out “Which diet works best?” by reviewing the results of 59 individual studies. These studies included various dietary recommendations such as low fat, low carbohydrate, etc. Which of these recommendations was dominant? No one. There were no major differences between the diets, and success depended entirely on what the person could stick to. In other words, practicality was king.
Likewise, one of the most common questions asked by aspiring fitness enthusiasts is, “Which is more important: diet or exercise?” With practicality in mind, we decided to take a look at the evidence.
Calorie Tutorial
Physiologically, weight loss and weight gain are associated with calorie intake and expenditure *. For this reason, it is important to understand the basics of calories . Simply put: we lose weight when we consume fewer calories than we expend. Conversely, we gain weight when we consume more calories than we expend. To lose one pound of fat, we must create a 3,500 calorie deficit, which can be achieved either through exercise or through diet.
* As an aside, it is worth noting that some argue that carbohydrates and insulin are the culprit for weight loss and weight gain in the so-called “insulin obesity hypothesis.” While controlling both carbohydrates and insulin may be important for some people, this hypothesis has been completely disproved .
Let’s say a 200 pound man wants to lose one pound in a week. With exercise alone, he needs to run about 3.5 miles a day (or 24.5 miles) if his diet stays the same. With diet alone, he needs to cut 500 calories a day (the equivalent of two frappuccinos at Starbucks), given the same exercise regimen. In theory, both should achieve the same results.
But in the world of fitness, theory and reality are not the same thing, because theory doesn’t account for adherence. We don’t live in a magical house with a gym, Whole Foods, and a personal staff of nutritionists and trainers. Instead, in our daily life, we stay busy with our own devices. What happens then?
What the research says
Dr. John Briffa, who runs an excellent health blog, analyzed a study examining weight loss without diet therapy here . He explains:
In this study, 320 postmenopausal women , ranging in weight from normal to obese, were randomized to either the supplemental exercise group or the no supplemental exercise group (control group). Participants in the exercise group were instructed to engage in moderate-intensity aerobic exercise for 45 minutes, 5 times a week for a year. Both groups (extra exercise and control group) were instructed not to change their diet.
At the end of the year, the exercise group was found to have lost an average of 2 kg (4.4 lb) fat compared to the control group. I would say that many of us would love to lose a few pounds of fat. But now I would also like to focus on what these women had to do to cope with this loss.
While the exercise group was instructed to exercise 5 times a week for 45 minutes, they actually did the exercise an average of 3.6 days per week. The total exercise time averaged 178.5 minutes per week. We can multiply this by 52 to get the total exercise minutes for the year, and divide by 60 to convert to hours. Thus, we get a total of just under 155 hours. That’s roughly 77 hours of exercise for every pound of fat lost.
Most people would give up on the idea of exercising for 77 hours to lose 1kg of fat. (Or the equivalent of 35 hours to lose 1 pound for us Americans.)
But what about doing exercise and keeping track of your diet at the same time?
One study, published in the International Journal of Obesity and Related Metabolic Disorders , involved trained subjects who were asked to track food intake and energy expenditure . On paper, the subjects were running a general calorie deficit. However, when researchers looked at the empirical changes, no weight loss actually occurred. As it turned out, the subjects simultaneously underestimated the calorie content and overestimated it.
Compare the above studies to a hilarious self- experiment by a nutritionist who followed the Twinkie Diet and subsequently lost 27 pounds in 10 weeks. (Pro tip: Don’t try this at home.)
Why exercise-focused regimens are relatively ineffective for weight loss
If you are confused by the above information, don’t worry. There is a simple explanation behind this, which we will divide into two parts.
Reason 1. By and large, calorie expenditure during exercise is relatively low.
To understand why exercise-focused weight loss programs can be ineffective, it is important to understand how we burn calories per day .
We spend most of our calories every day just to survive. This is known as the resting metabolic rate. The Kutch-McArdle formula , which takes into account the percentage of body fat, is the most accurate way to calculate this number, which is equivalent to:
9.81 x Your Lean Mass + 370 Calories Per Day
Let’s say you’re a 200-pound male with 30% body fat. You are spending 1,743 calories a day just by staying alive. (200 x (1-30) * 9.81 + 370 calories)
He will spend about 10% on top of what is known as the heat effect of food (TEF): the number of calories he spends digesting and absorbing his diet.
Add another 10% via a metabolic process known as NEAT (No Exercise Adaptive Thermogenesis ). This is the number of calories spent on things like fidgeting. Unfortunately, this can be very different from person to person.
This means that, even without getting out of bed, our subject has already consumed 2,100 calories.
Now add another 10% for getting out of bed and going about your daily routine and it has already burned 2,300 calories.
Adding exercise to the equation is unlikely to affect his total calorie expenditure; most of the work is done before he puts on his sneakers. I am not saying that you should not exercise, but rather, it is important to understand where most of your calorie expenditure is coming from. You wouldn’t use the paper route to increase your $ 100K a year salary, would you?
Reason 2: People are awful at their input and output calories.
Take a look at another studypublished in the Journal of Sports Medicine and Physical Fitness , in which researchers asked subjects to exercise, estimate their calorie expenditure, and then sent them to a buffet. The subjects were asked to eat the amount of food they thought they burned in calories. (Note: where can I subscribe to one of these?)
As a result, the subjects ate 2-3 times more calories than they burned.
The takeaway from all of this information is that calorie expenditure does not matter much, and people tend to rate both expenditure and consumption badly.
How to effectively combine diet and exercise
To understand how to combine diet with exercise, I reached out to my friend and obesity expert, Dr. Yoni Friedhoff . Yoni runs one of the largest obesity clinics in Canada and has helped countless people lose weight through health and fitness approaches. Yoni explains:
Most people I see struggle a lot more with their kitchen than their gym. They will readily find 30 minutes or more a day to go to the gym, go for a walk, or simply increase their daily activity by parking further away and going upstairs more often than packing lunch, preparing ingredients, preparing dinner. , or keeping a food diary. I think partly because the whole world believes in it – no doubt fueled by shows like The Biggest Loser and the huge money the food industry spends communicating about ‘balancing’ energy in and out, but also because that we don’t get an endorphin release from chopping vegetables or washing dishes.
Then he goes on to elaborate.
Most people want to lose weight and improve their health, so gyms and kitchens are essential. However, if weight is the most important thing, I would never leave the kitchen to find time to exercise. Instead, take all the time you think you’re willing to spend in the gym and officially devote at least a third of that time to the kitchen. In terms of optimal amounts, a person should like the life he is living if he is going to support it, so what is right and optimal for one person will be too little or too much for another. The simplest question is, “Can I live like this forever,” and if the answer is “no,” you need to change something.
Given that Yoni has worked with a huge number of successful patients, I asked about their community.
The most successful are those who accept both consistency and imperfection. Consider starting a weight control or healthy lifestyle program as if you were doing a martial art. You never expected to get a black belt from the start. Instead, you would start with really simple movements that you do over and over again, you would fall, and that would be expectation, not frustration. And then slowly but surely you will get better and better at it. The same is true for any skill set, including a healthy lifestyle, and just as you might imagine a jumping hook jumping when you start out in your dojo, that doesn’t mean you can just do one. It’s the same with a healthy lifestyle. Sure, you may have a mental picture of what your healthy lifestyle should look like when you’re done, but achieving this will be slow, difficult, and will involve many falls.
He also shares some other great tips.
Never dine out of your home unless someone is shopping. It is better to do less exercise regularly than do more intermittently – there is little research on diet or exercise that is long enough to translate into recommendations or conclusions for a lifetime. Spending 2-3 minutes a day with a food diary is likely to have a bigger effect on your weight than 30 minutes at the gym.
Where to go from here
So, I gave you a lot of information that exercise, as the only means of losing weight, is relatively ineffective or even counterproductive. Here are the steps you must take to be successful.
- Determine how many calories you burn each day. You can use the ExRx calculator here . Calculate this from your body fat percentage for accuracy. If you don’t know your current body fat percentage, check out this helpful article by Lee Peel .
- Reduce your calorie intake by 20% of your maintenance calories. Every time you decrease your calorie intake, it is helpful to increase your protein at the same time to stay full. (Protein also has a higher thermic effect of food than any macronutrient, which means your body needs to spend more energy digesting it than carbohydrates or fats.) How much protein should you eat when you’re in a calorie deficit? Nutritionist Alan Aragon recommends determining your target body weight and calculating it in grams. For example, if you are a 200 pound woman looking to lose up to 120 pounds, consume at least 120 grams of protein per day.
- Once you’re comfortable with counting calories, consider switching to counting macronutrients instead. Focusing on macronutrients rather than calories is a good way to break the fact that people (myself included) often translate exercise and food into the same currency: calories. You can learn all about the basics of how to count macros here .
You will notice that the weight loss guidelines above do not mention exercise. But even though you do not have to be taken into account in the exercise consumption or consumption of calories, you should still include them as practical as possible.
“Of course, weight is lost in the kitchen,” says Dr. Friedhoff. “But health is achieved in gyms.”