Aims: Nowadays, the prevalence of obesity is increasing, not only in developed but also in developing countries. Using an alternative meal in a day is one of the most popular diets. The objective of the current research was to investigate the level of weight loss by using a cereal diet for breakfast.

Materials & Methods: In this interventional study which was done in February 2013, 120 obese and overweight patients, who were referred to the Tehran Municipal Health House, randomly assigned to control and experimental groups. 30 to 45 grams of cereal with one glass of milk were prescribed for experimental group for breakfast and dinner and the control group had their regular diet. All samples were weighed, after 14 days period of study under the control of nutrition experts. The obtained data were analyzed by Mann-Whitney U and independent T tests.

Findings: Mean weight of both groups was decreased after the intervention. The decreasing was significant in experimental and non-significant in control group. Mean difference of decreasing in Body Mass Index (p=0.005) and weight (p=0.078) parameters was significant and in waist (p=0.63) and hips (p=0.55) sizes was non-significant between two groups.

Conclusion: Using breakfast cereals is effective in reducing weight in obese patients without any side effects.