Once considered a problem specific to countries with high income, nowadays overweight and obesity are on the rise in low- and middle-income countries, especially in urban settings.
What causes obesity and overweight?
• an increased intake of energy-dense foods that are high in fat and sugars, and
• an increase in physical inactivity due to the increasingly sedentary nature of many forms of work, impacted by transportation and increasing urbanization.
Obesity is a serious health concern because it significantly increases the risk of certain lifestyle conditions – various types of chronic diseases such as diabetes, cardiovascular disease, hypertension, strokes, certain cancers, the Alzheimer disease.
How can overweight and obesity be reduced?
Overweight and obesity are largely preventable. At its simplest, losing weight means burning more calories than you consume.
The most common approach is to eat healthier foods and get regular physical activity. More specifically:
• limit the total fat and sugar intake, while increasing consumption of fruit, vegetables, as well as legumes, whole grains and nuts;
• engage in regular physical activity that can help you lose weight and body fat. WHO (World Health Organization) recommends 60 minutes a day for children and at least 150 minutes spread through the week for adults.
You can either lose weight by limiting the number of calories you eat, or burn extra calories with exercise. Combining these two approaches works best.
Don’t rely on fad diets which may promise fast results, but at the expense of being unhealthy and with little nutritional value. They will ultimately fail in the long run.
To achieve weight loss, the American Diabetes Association (ADA), American Academy of Clinical Endocrinologists (AACE), and National Academy of Nutrition and Dietetics all recommend exercise as an integral part of any weight loss program.
How much physical activity do you need?
It really depends on whether you are trying to maintain or lose weight. Walking is the most convenient way to add more physical activity in your life. 30 minutes of daily walking can maintain your weight, plus various powerful benefits for your body and brain.
Exercise can increase metabolism, or how many calories you burn in a day. If you are trying to lose more weight and body fat, include some form of cardio or HIIT in your workout routine.
Other simple and practical ways to include more physical activity in your life include riding your bike to work or just casually, taking the stairs instead of the elevator, some household activities like cleaning, gardening and even cooking.
Does exercise alone improve weight loss?
Most, but not all, study data indicate that exercise alone plays a very small role in weight loss.
A joint position statement of the American College of Sports Medicine and the ADA states that the “recommended levels of PA [physical activity] may help produce weight loss. However, up to 60 min/day may be required when relying on exercise alone for weight loss.”
The 2016 AACE and the American College of Endocrinology recommendation for patients with obesity include “aerobic training of ≥150 min/week of moderate intensity, with better outcomes when increasing the amount and intensity of exercise.”
Is there any difference between aerobic and resistance training, or the intensity of activity, in losing or maintaining weight loss?
Following an 8-month trial, weight loss occurred with aerobic training to a more significant degree than with resistance training. Adding resistance training did not significantly contributed to additional weight loss compared to aerobic alone. However, increasing the aerobic intensity level or duration contributed to additional weight loss during the 8-month trial.