A diet rich in vegetables enhances your health and can help you manage your weight, but you cannot subsist on vegetables alone. Even when your goal is fat loss, you need healthy dietary fat and lean protein to support optimal body functioning. Eating only vegetables for a month may lead to some fat loss, but you may also lose lean muscle in the process, so it isn't the best way to reach your goals.
How Vegetables Help
To lose fat, you must eat fewer calories than you burn. Eating a lot of vegetables helps you lose fat because they tend to be high in fiber and water while providing few calories per serving. As a result, they can make you feel like you're eating a lot of food without taking in tons of calories. You can't just eat more vegetables and hope to lose weight, though. They must replace higher calorie foods in your meal plan.
Strive for Balance
Replacing high-calorie foods, such as white bread, sugary treats and chips, with vegetables reduces your daily calorie intake and can help you lose fat. But vegetables shouldn't replace every food you eat. While they are high in nutrients, vegetables don't provide all the essential amino acids you need for tissue growth and maintenance. Most also contain very little fat, a nutrient you need to support vitamin absorption and hormone production. Although the watery, fibrous nature of vegetables can fill you up -- they may not keep you satisfied for hours like protein and fats do. You'll find it hard to maintain a diet of vegetables only, which could lead you astray from your program way before a month is up and significant fat loss is had.
Too Low of Calories
Just eating vegetables may leave you eating too few calories for good health. While a calorie deficit is valuable to fat loss, eating too few causes risks to your health. When you don't get enough calories, your body starts to use your own body tissues for fuel -- namely muscle tissue. You may see the numbers on the scale drop, but you're likely losing a lot of valuable lean muscle along with some fat. The diet may also leave you crabby, hungry and low in energy because you're depriving yourself of necessary nutrients. A daily calorie intake of just 900 to 1,000 calories per day is considered very low calorie.
A Better Approach
Eating just vegetables for a month can lead to some fat loss, but it isn't an optimal amount nor is it a healthy approach. Instead, you're better eating moderate portions of lean proteins such as egg whites, white fish, lean beef and chicken breast along with your vegetables to provide ample nutrients and feelings of satiation. A small serving of fat with most meals, such as a teaspoon of olive oil, a half-ounce of nuts or an eighth of an avocado will also advance your fat loss. Use vegetables to form the bulk of your meals, though, so you keep your daily calories low, but not so low that you endanger your health and muscle.