The National Weight Control Registry (NWCR) was established in 1994. It is the largest study into long-term weight loss programs. The principal researchers are Rena Wing (Brown Medical School, Rhode Island) and James Hill (University of Colorado). There are now over 10,000 participants enrolled in the study. 
To be eligible to enroll in the study participants must be at least 18 years have lost at least 13.6 kg (30 lbs) of weight and kept it off for at least one year.
According to the researchers “almost nobody is on a low-carbohydrate diet” and they have looked “very hard to locate them. We can’t find more than a handful of people who follow the Atkins program in the registry”.
Atkins endorsed the Registry in his books and website so it cannot be argued that low-carbohydrate dieters are not aware of the study.
Most participants report continuing a low calorie, low fat diet and doing high levels of activity to maintain their weight.
- 78% eat breakfast every day.
- 75% weigh themselves at least once a week.
- 62% watch less than 10 hours of TV per week.
- 90% exercise, on average, about 1 hour per day.
- Only 4% report never having breakfast.
The suggestions from the NWCR to successfully maintain a healthy weight-control program are:
engaging in high levels of physical activity
eating a diet that is low in calories and fat
self-monitoring weight on a regular basis
maintaining a consistent eating pattern; and
catching “slips” early