There’s no other choice: you have to match your food intake to your nutritional needs to achieve your weight and health goals. While exercise is a priceless part of the journey toward a healthy and fit-looking body – and may increase the total amount of food you can eat in a day without gaining weight – there is a limit to what it can do by itself, and to how much in a day is good for you.
Many of us try to lose weight, and to reach that goal we use different means, some being diets (that can be dangerous to your health), exercise, chemical additives, medicine and even surgery – all to lose weight. Being thin has become a desirable goal as obesity becomes so common. And no wonder: unhealthy food being widely available, cheap, rich in fats, sugar and salt; a variety of TV programs show us how to make gourmet meals with tons of chocolate, butter, whipped cream, rich meats, etc.; commercials tend to promote the fattiest, most harmful kinds of food; and binge-eating scenes in movies are as frequent as sex scenes.
In order to lose weight, you need only one thing: balance, which means expending a certain amount of energy each day, and consuming what you need. It sounds like simple arithmetic, but it really isn’t. While eating is very simple, matching your physical activity takes a little more thought.
Diet and exercise – how do they affect each other?
Energy expenditure can happen in certain ways:
- Basic metabolism: that same energy “burnt” to keep basic functions keeping us alive while resting.
- Energy spent during digestion, processing and transference of food (thermal effect of food).
- Natural daily exercise (movements, walking, anything physical) and initiated exercise.
Therefore, if the amount of energy used is bigger than the amount being consumed – the process of weight loss will be realized.
According to many researches, it seems that exercise alone, with no change in your diet – especially among those with weight gaining tendencies – won’t achieve the negative energy balance that could cause weight loss. It’s true that if an overweight person would start engaging in intensive physical activities like triathlons, riding mountain bikes, marathons etc., he/she would be likely to affect the energy balance to some extent. Unfortunately most people, especially the overweight among us, don’t participate in those kinds of activities.
More importantly, weight loss by the numbers is only part of the story – the ultimate goal is health, and weight loss efforts concurrent with poor dietary choices constitute a ticking time bomb that may result in fatigue, injury, illness, and even significant weight regain.
So how do nutrition and exercise affect each other? It is known that the ratio of metabolism to body weight varies between body types, and is dependent on genetics, initial weight, and activity level beyond exercise, therefore making it necessary for some people work harder to reach their goals. Some overweight, sedentary individuals respond immediately to an increase in physical activity and “right-sizing” of their eating, later reaching a plateau in their weight loss as muscles get used to the physical activity (requiring some patience and perhaps introduction of new activities). Others find that their metabolism is naturally slower, and that just as this contributed to their initial weight gain, it will also require a doubling of their weight loss efforts; in some cases, the excess weight – especially if severe – may mean that the exercise they do cannot initially be as intense as is ultimately needed for optimal results.
But even so, it’s important to stress that exercise, even the lightest kind, will most definitely improve your health – by helping to balance your blood pressure, blood sugar, cholesterol, and blood triglycerides – and will support weight loss achieved with a nutritionally sound program, both in the short term of the weight loss process, and in the long term of maintaining the weight you reached. Additionally, it was recently published in the prestigious journal Lancet that a lack of exercise is responsible to 10% of all early mortality cases (deaths). According to that same research, the effect of no exercise is especially dramatic in relation to early coronary heart disease, type 2 diabetes, breast cancer, and colon cancer.
Moreover, even the mildest exercise will keep the body’s composition, meaning it would prevent excessive decomposition of muscle tissue, in a way that would cause the weight loss to happen mostly by breaking down fats. Even mild exercise will cause a slight increase in muscle mass, which would have a slight effect over the metabolism in the long run. We know that a well-developed muscle “burns” more energy; therefore a change in that direction will contribute to weight loss, beyond the initial exercise itself.
So why is it important to combine exercise with our diet?
Research has shown that the healthiest weight loss is obtained by a combination of exercise with a sound diet, to achieve the longest-lasting results in weight loss and to guard muscle mass.
The main reason is that weight loss achieved only by dieting may cause your muscle mass to shrink and metabolism to slow down, which decreases the energy “burn”. Unless you engage in extreme “calorie-cutting,” working out regularly counteracts much of the natural decrease in metabolism resulting from the diet, both in the short and long run, which would enable you to continue losing weight, maintain lost weight longer, AND improve your overall health.
While the level of exercise recommended for weight management is generally “every day for about 30-90 minutes, at moderate intensity,” initially every little bit counts and accumulates as you work your way up to the target level. However, this process must be paired with efforts on the nutrition side. Each person has a different reaction to activity and/or rightsizing of nutritional intake, and the equation is not only influenced by the duration and intensity of your workouts, but most often also by your age, gender, experience with previous diets, medical condition, and of course, the composition of your diet.