This is a summary of a study published in Obesity Facts. The European Journal of Obesity. Vol. 3(2). 2010.
For obese people, abdominal fat (or visceral) is one of the biggest health issues. There is a strong correlation between the incidence of cardiovascular diseases and high levels of visceral fat and it is therefore a major health concern.
The study of Vissers et al. (2009) involved 79 obese adults (61 completed the study), who were randomly divided into 4 groups:
Group 1 received a diet only program (DIET)
Group 2 received a diet plus traditional fitness program.(FITNESS)
Group 3 received a diet and a Whole Body Vibration machine program (WBV)
Group 4 made no changes to their lifestyle (CONTROL).
Each group followed the intervention for six months and then had a six month follow up. Body composition and metabolic features were measured at three, six and 12 months. One measurement performed was the determination of visceral fat tissue.
In all three study groups (DIET, FITNESS and WBV) bodyweight decreased significantly (5-10%).
In measurements taken after the 6 month follow up only the FITNESS and WBV groups managed to maintain their weight loss of 5% or more in the six month follow up period. The WBV group maintained a weight loss of over 10 %.
The WBV group lost twice as much visceral fat after six months, when compared to the FITNESS and DIET groups. The decrease in visceral fat also remained at the same level in the WBV group after 12 months, while the DIET and FITNESS groups returned to their baseline values after 12 months.
Q & A?s
Why did the WBV group not return to baseline values as the other groups did after 12 months?
It may be related to the hormonal changes that WBV training may cause. An animal study (Rubin et al. 2007) showed that vibration caused the adipogenesis (creation of fat cells) in mice to drop by 27%. Therefore the vibration prevented the creation of new fat cells. Research is currently being conducted to fully understand the underlying principles of these possible changes in humans.
Why did the DIET group lose more visceral (abdominal) fat than the FITNESS group?
The human body needs energy during and up to 24 hours after fitness training. This is called the after-burning effect. In order to get that energy, the human body will burn the easy fat tissue (the subcutaneous fat) first rather than visceral fat. The results which showed that the FITNESS group lost more body weight than the DIET group is caused by this reduction in subcutaneous fat tissue.
Why did the CONTROL group lose visceral fat tissue during the first six months and then gain visceral fat tissue over the next six months?
The CONTROL group knew they were involved in a study which would involve their weight and fat tissue being measured after the first six months. This may have caused them to eat healthier, eat smaller meals, etc. This would result in a minor decrease in visceral fat tissue. During the second six month phase of the study, the group could be aware that the others being tested were not doing any interventions, so they would feel comfortable in adopting their previous lifestyle, resulting in an increase in visceral fat tissue.
Adding Whole Body Vibration (WBV) Training to a low calorie diet can help to achieve a sustained long term weight loss and can reduce visceral adipose tissue in obese adults more than aerobic exercise with a low calorie diet.