When trying to lose weight the question is, will this diet work? The answer to that depends on the diet's prescribed caloric intake as well as the types of foods it recommends you eat. Not all diets are created equal and simply entering a calorie deficit doesn't always equal success. The type of food you eat can sometimes be just as important as the amount of calories you take in.
Calorie Deficit = Success
Though the types of food you eat are very important to your overall health and weight loss goals, the most important factor that determines whether or not a diet will work is if it puts you into a calorie deficit.
If you're burning more calories than you're eating, you will lose weight, there's not a lot of ways around this. Use a tool such as the calorie calculator to ensure that you're eating a proper amount of calories when going on a diet.
The types of food a diet recommends can also have a big impact on its success. Some diets remove entire groups of foods such as carbs or fat while other limit you to only one type of food: cabbage soup diet. Both of these examples are somewhat extreme measures and should be avoided.
A diet that works and is healthy will be balanced. It will allow you to eat all foods including fats, carbs and proteins as long as you stay under your daily calorie allowance. Eating foods from a variety of sources will allow you to take in 100% of your daily nutrient needs.
Foods You Love
A diet that works will also not restrict the foods you love. If you can't live without cookies or ice cream, how do you expect to go on a diet that won't allow them. You can have some unhealthy snacks as long as it's done in moderation and in addition to an otherwise healthy diet.
Permanent Weight Loss
Dieting isn't about the fastest way to lose weight. It's about finding a way to lose weight in a healthy manner that's also permanent. The best diet will cause slow, controlled weight loss in a way that is sustainable.
Once you've reached your target weight, the diet program should help you continue a healthy lifestyle instead of going back to your old, unhealthy ways. If you don't find a way to continue your new, healthy habits, you'll forever be chasing weight loss goals which isn't a fun life to live.