Fat loss without muscle gain is not a difficult process. If you burn more calories through activity than you take in by eating, your body makes up the difference by burning fat. You can do this by reducing your caloric intake or increasing the number of calories you burn through exercise. Although exercise does lead to muscle gain, the major muscle gain comes from resistance exercise. If you adopt a weight-loss diet with little to no resistance exercise, you can shed fat without adding muscle.
Start keeping a food journal. Write down what you eat, when you eat and how much you eat. At the end of each day, use an online calorie calculator or a calorie counting app on your phone to compute the number of calories you ingested.
After three days, add the number of calories you ate each day and divide the total by three to get the average number of calories you consume per day.
Adopt a weight-loss diet that reduces your daily calorie intake by 500. This will result in you losing about one pound per week. Focus on reducing your calories by cutting out high-calorie, low-nutrient foods, such as those made primarily with sugar and white flour or those fried in oil.
Pre-plan, and even pre-prepare, your daily meals when possible. This is much easier than trying to track your calorie intake on the fly over the course of the day.
Continue to track your food intake each day. Don't forget to write down the calories you ingest through liquids as well as food. Even your morning cup of coffee adds calories if it is filled with cream and sugar.
If you want to increase your rate of weight loss, add a daily session of cardiovascular exercise. Although this will strengthen and tone your muscles, it's unlikely to add any mass or bulk to your existing muscle, especially if you stick to lower impact exercise such as walking or swimming. These activities burn approximately 300 and 450 calories per hour, respectively, when done at a moderate pace. Adding just five 30 minute sessions per week of these activities can help you lose an extra two pounds a month.