Why Is Losing Weight So Hard?

If you eat less and run more, you’ll lose weight and quickly, right? Maybe not. New research again confirms that weight loss may be more complicated than simply “ kilojoules in” and “kilojoules out.”

The Obesity Research & Clinical Practice journal recently published a study from York University that examined dietary and physical activity data spanning decades from the National Health and Nutrition Survey (NHANES). NHANES is a program that surveys different groups of people from year to year with the aim of assessing the health and nutritional status of adults and children in the United States. NHANES uses both self-reported data and physical examinations.

Researchers found that between the years 1971 and 2008, body mass index (BMI), total kilojoules intake, and carbohydrate intake all increased, while fat and protein intake decreased. Researchers also noted that from 1988 to 2006, the surveyed participants increased how often they were physically active during their leisure time.

This means people were eating more calories but exercising more—and gaining weight. Most surprisingly, the researchers noticed that an individual in 2006 compared with his or her counterpart in 1988—with the same age, gender,  KJ intake, and activity level—had a higher BMI by 2.3 kg/m2 than his or her 1988 counterpart. So over the span of about 20 years, the calorie balance equation is off and people have gotten heavier.

This suggests there may be factors in addition to diet and activity that affect weight status. Emerging evidence indicates hormonal changes from lack of sleep and stress, environmental toxins, certain medications, low calcium status, the gut bacteria, and more may have an impact on body weight regulation, though more research needs to be done to figure out precisely how these factors affect weight status.

Although this study indicates BMI increased for a given caloric intake and activity level from 1988 to 2006, the diet and activity data used was primarily self-reported, which typically is not entirely accurate. Also, NHANES is unable to follow the same people from year to year, so causality is unable to be established.

In the meantime, what can you do to maintain a healthy weight? Some simple suggestions can start you out on the right foot.

Decrease kilojoules: Add vegetables to every meal. You can start each meal with a salad or create meals centered on vegetables, such as a veggie-packed stir-fry. Eat fruits and vegetables for snack time.

Increase activity: Your running is a great start. But it isn’t enough if you aren’t moving the other 23 hours in a day. Take the stairs whenever possible. Get up from your desk and do a lap around the office every hour.

Aim for 7 to 8 hours of sleep every night. For nights when you’re low on sleep, sneak in a 20-minute catnap.

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