It’s difficult for many individuals to lose weight, but keeping it off is even more challenging. Most people who lose an enormous amount of weight regain it after two or three years.
The theory behind regaining lost weight suggests that people who reduce the number of calories they eat to lose weight experience a decrease in their bodies’ capacity to burn calories, making it harder to shed weight over time.
This study aimed to investigate how healthy diets containing small or large amounts of red meat affect weight maintenance and, secondarily, body composition (DXA), resting energy expenditure, and cardiovascular risk factors.
Weight loss maintenance has been associated with a more significant reduction in metabolically active lean tissue mass and resting energy expenditure (REE).
The greater the protein content of a diet, the less likely it is to result in a loss of lean body mass and a decline in REE during weight loss and energy restriction. Compared with lower-protein diets, higher-protein diets may reduce weight regain after weight loss.
In industrialized countries, red meat accounts for about half of meat consumption and 40% of dietary protein and contains more than 20% of all essential amino acids.
Observational studies have shown, however, that diets high in meat, particularly red meat, increase the risk of obesity, diabetes, and cardiovascular disease. Most of these studies compare meat and non-meat eaters cross-sectionally, retrospectively, or longitudinally.
Healthy males and females with overweight or obese, aged 18 to 65 years, were recruited for this study.
There was an 8-week rapid weight loss period for 108 adults with a body mass index of 28–40 kg/m2 (45 males/63 females) in this 5-month parallel randomized intervention trial.
For 12 weeks, those who lost 8% body weight continued ad libitum weight maintenance diets: a moderate-protein diet containing 25 grams of beef/day (B25, n = 45) or a high-protein diet containing 150 grams beef/day (B150, n = 35).
All subjects were given four sachets of any combination of the following VLCD formula products (LighterLife) for eight weeks.
As a result, the higher-protein arm had an additional 25 grams of whey protein powder, resulting in an average daily intake of approximately 700 kcal with 77 grams of protein (44%), 52 grams of carbs (30%), 18 grams of fat (23%), and 14 grams of dietary fiber (4%).
Results of the Study
According to the protocol analysis (n = 69), mean body weight, mean fat mass, and mean body fat content decreased during maintenance, while mean lean mass and mean REE increased, with no significant differences between groups.
An intention-to-treat analysis with multiple imputations for dropouts showed similar results.
Again, there was no significant difference in cardiometabolic risk factors between groups, with a general pattern of a reduction during weight loss and a return to baseline during weight maintenance (despite a mild decrease in weight and fat mass).
The effects of healthy diets containing a little or a lot of unprocessed beef on body weight, energy metabolism, and cardiovascular risk factors during the first three months after clinically significant rapid weight loss are similar.