Putting weight back on after a successful diet is a common problem. One of the reasons it happens is that the human body reacts to the loss of fat by slowing its metabolism – this results in it burning less calories than it would normally. Indeed, many people are unfortunate enough to regain more weight than they originally lost.
A prevailing theory states that all calories work in the same way. However, a recent study has shown that this is not necessarily so. Instead, it suggests that reducing our intake of carbohydrates can give a boost to our metabolism. This, in turn, makes the body burn more calories. If correct, this has implications for the many people who regain weight after a successful diet.
The study was done on 100 overweight people who had all recently dieted and lost approximately 15 percent of their body weight. These people were then split into two groups and put on either a low or high carbohydrate diet for 25 weeks. The calorie intake in both the groups was adjusted throughout the course of the study so that no-one gained or lost significant amounts of weight.
Over the period of the study, the energy expenditure of the participants, i.e. the calories they were burning, was measured accurately. The results showed that those on the low carbohydrate diet burned about 300 calories more per day than those on the high carbohydrate diet.
This was thought to be because the consumption of processed carbohydrates is known to cause high insulin levels. This makes the body store excess calories as fat, and also slows its metabolic rate. These two factors cause an increase in weight.
However, by eating less of these refined carbohydrates, the body’s metabolism is increased with a corresponding increase in the amount of calories it burns. The more calories burned, the greater the amount of weight lost.
A third contributing factor was that people on the low carbohydrate diet had a much lower level of ghrelin, a hormone that reduces the rate at which calories are burned.
So, on the face of it, this seems like the way for successful dieters to avoid the frustration of seeing that all hard lost fat quickly piling back on.
However, the following should be noted:
- It wasn’t just any low-carbohydrate diet. Rather, it was a very specific eating plan with the nutrient content calculated to the exact gram. Accordingly, a lot of people who give this type of diet a try will probably not have the same level of success as they simply don’t know precisely what to include in it
- The carbohydrates provided on the diet weren’t the usual highly processed ones typically found in the stores. They were all high quality foods that had undergone no, or minimum, amounts of refining. This is a critical point – the success of this diet is entirely dependant on eating the right type of carbohydrates, such as nuts, fruit and non-starchy vegetables. These will have the desired effect as they provide an adequate intake of phytonutrients, antioxidants, minerals, vitamins and fiber
The takeaway message from this is much the same as that from many of the articles on this site – successful weight-loss, and subsequent maintenance of that loss, is dependent to a very large degree on the avoidance of highly refined carbohydrates, i.e. the products of the processed food industry.