Jakubowicz, who worked on the study with US scientists from Virginia Commonwealth University in Richmond, said that:
"Most weight loss studies have determined that a very low carbohydrate diet is not a good method to reduce weight."
She explained that the low carbohydrate diet, "exacerbates the craving for carbohydrates and slows metabolism. As a result, after a short period of weight loss, there is a quick return to obesity."
Only 5 per cent of low carbohydrate diets are successful after two years, and most of them do not address addictive eating impulses, said Jakubowicz.
The findings of this study, suggested the researchers, showed that the long term effectiveness of a diet depends on how well it creates a sense of fullness and brings down cravings for "carbs".
For the study, the researchers enrolled 94 obese, physically inactive women and put 46 on a very low carb diet and 48 on their new diet for 8 months. Both diets were low in fat and total calories, but they had different ways of taking in carbohydrate over the day.
The women on the very low carb diet ate 1,085 calories a day allotted as 17 grams carbohydrates, 51 grams protein, and 78 grams of fat. On this diet, breakfast was the smallest meal, comprising 290 calories and only 7 grams of carbohydrate, such as bread, fruit, cereal and milk. Also, the women on this diet could only eat up to 12 grams of protein in the morning, such as meat and eggs.
On the new "big breakfast" diet, the women ate 1,240 calories a day alloted as 97 grams carbohydrates, 93 grams protein, and 46 grams of fat (compared with the other diet, these women ate less fat, but more carbohydrate and protein every day). On this diet, breakfast was the largest meal, while lunch comprised 395 calories (including 34 grams of carbs and 28 and 13 of protein and fat respectively), and dinner contained only 235 calories (5 grams of carbs, and 18 and 26 of protein and fat respectively).
For the first 4 months, the study focused on weight loss, and on weight maintenance for the second 4 months. The results showed that:
- After 4 months, the women on the very low carb diet had lost an average of 28 pounds (12.7 kilos).
- After 4 months, the women on the big breakfast diet had lost an average of nearly 23 pounds (10.4 kilos).
- At this point, there was no statistically significant difference in the weight loss profiles of the two groups, despite these apparently large differences in the averages, said the researchers.
- After 8 months, the women on the very low carb diet had regained an average of 18 pounds (8.2 kilos).
- After 8 months, the women on the big breakfast diet had lost another 16.5 pounds (7.5 kilos).
- Overall, the women on the big breakfast diet lost more than 21 per cent of their body weight, while the women on the very low carb diet only lost 4.5 per cent.
- The women on the big breakfast diet reported feeling less hungry, especially before lunch, and they reported having fewer cravings for carbs compared with the women in the very low carb group.
The researchers suggested that the big breakfast diet was more effective at helping the women lose weight over the period of the study because it controlled appetite and cravings for carbohydrate foods containing sugar and starch.
Jakubowicz also said the big-breakfast diet was healthier than a very low carb diet because dieters ate more fruit and therefore got enough fiber and vitamins. She has been using the diet successfully with patients for over 15 years, she said.
