Maybe you're thinking of eating only fruits and vegetables for a month in an effort to lose weight quickly. In a culture that values instant gratification, when people want the most success in the shortest amount of time, is it any wonder that people are inclined to try these kinds of fad diets?
Defined by the American Academy of Family Physicians as typically unhealthy eating plans that promise great results but aren't good for long-term weight loss or even your overall health, fad diets work in the short term because they usually require extreme calorie restriction.
Before you start that fruit-and-veggie-only eating plan, it might be time to ask yourself: Is this a fad diet? And if so, what are some healthier alternatives?
Yes, you can definitely lose weight from eating only vegetables for a month or with any other meal plan that restricts your calories. But a diet that is healthy in the long run requires sufficient calories, protein and fat that you might be cutting out of your diet.
Cutting Calories for Weight Loss
According to numbers, a calorie deficit of 3,500 calories — whether created through diet or exercise — may result in losing 1 pound of fat.
So depending on how many calories you cut from your diet when you switch to eating only fruits and vegetables for 30 days, you could lose a lot of weight. But most people who try a diet that's too strict will have trouble sticking with it, and they may even gain the weight back once they go back to their old eating habits.
Does this mean a diet consisting entirely of fruits and vegetables is too restrictive and possibly a fad diet?
Well, it depends on your definition of fruits and vegetables. By strict definition, beans and peas are considered vegetables, and nuts are considered fruits. If you eat these, then no — your diet could actually be very healthy. Making a point of including these in your diet will give you the calories, protein and fat you need to make your diet both satisfying and sustainable.
The Right Nutrients
Fruits and vegetables are rich in vitamins and minerals, but a healthy diet also includes a healthy balance of macronutrients — that is, the nutrients that your body needs in large quantities and that provide calories for energy. The three macronutrients are carbohydrates, fat and protein.
Protein is an important part of a diet for weight loss because it keeps you full and increases your metabolism to burn more calories, according to the American Academy of Family Physicians. You can easily get substantial protein in an all-vegetable diet as long as you go for the right vegetables.
In fact, the United States Department of Agriculture recommends that even meat eaters vary the protein sources in their diet and make beans, peas or soy products the main part of their meal often. Try including lentils, chickpeas, black beans, kidney beans, pinto beans or edamame as part of your all-vegetable diet.
On the other hand, eating meat or poultry doesn't necessarily guarantee that a diet is sustainable either. When you eat chicken and vegetables for a month, it might give you the protein you need, but unless you're eating the right vegetables, such a diet might lack the carbohydrates and fats you need for energy.
Beans and starchy vegetables are great sources of complex carbohydrates. Avocados and coconuts are fruits that provide healthy fats.
This variety is important if your body is going to function properly, which is more important than how much weight you're losing. Take, for example, a fruitarian diet: Eating nothing but fruit and water can lead to rapid weight loss.
However, as Laura Jeffers, a registered dietitian with the Cleveland Health Clinic, points out, such a diet would result in nutritional imbalances and blood sugar spikes. A fruitarian diet, which she defines as being a diet made up of 50-75 percent of calories from fruit, should also include vegetables, seeds and nuts to provide fat and protein.
On the other hand, a diet without fruit and vegetables, which might be made up entirely of meat and grains, could provide easy access to all the macronutrients a body needs but be lacking in essential vitamins, minerals and fiber.
Vegetables for Weight Loss
The Centers for Disease Control and Prevention emphasizes fruits and vegetables for weight loss because they are full of water and fiber to help you feel full. Even if you're not eating only fruits and vegetables to get weight-loss results quickly, you can substitute them for other higher-calorie foods in your diet so that you're eating the same volume of food but taking in fewer calories.
This is important because, contrary to popular belief, it is the volume of a meal that affects satiety more than the number of calories in it. One cup of broccoli has 29.8 calories in it, while the same amount of pasta has 210 calories.
So if you're trying to lose weight, you don't necessarily need to cut out every other food group. Small changes such as mixing vegetables in with your pasta or bulking up a sandwich with lettuce and sprouts can make a big difference. These will decrease the calories you're taking in while increasing the amount of nutrients in your diet as well.
Calorie Counts Are Important
Whether you decide to try eating only fruits and vegetables for a month, or you simply make them the primary part of your diet, be sure you're getting enough calories — especially if you're losing weight.
When you take in too few calories, your body undergoes what's known as "adaptive thermogenesis," where you naturally start burning fewer calories because your system is trying to protect energy stores.
An online calorie calculator, such as the one provided by Mayo Clinic, can help you determine how much energy your body needs to sustain itself based on your age, sex, weight and activity level. If you're trying to lose 1 pound a week, subtract 500 calories from that number to create a deficit of 3,500 calories over the course of seven days.
Read more: How to Meal Prep for Weight Loss Like a Pro
Following fad diets for fast weight loss isn't a great idea for long-term sustainability, but if you switch to a varied diet of fruits and vegetables with enough calories, fat, protein and complex carbohydrates, you can get everything you need to be satisfied, nourished and energized while you trim down over time.
- American Academy of Family Physicians: "Low-Calorie Diets"
- Mayo Clinic: "The Difference Between Micronutrients and Macronutrients"
- U.S. Department of Agriculture: "Nuts"
- ChooseMyPlate.gov: "What Foods Are in the Vegetable Group?"
- American Academy of Family Physicians: "Nutrition for Weight Loss: What You Need to Know About Fad Diets"
- Mayo Clinic: "Counting Calories: Get Back to Weight-Loss Basics"
- ChooseMyPlate.gov: "Tips: Vary Your Protein Routine"
- MedlinePlus: "Complex Carbohydrates"
- Cleveland Clinic: "Fruitarian Diet: Is It Safe — or Really Healthy for You?"
- European Journal of Nutrition: "Increasing Vegetable Intakes: Rationale and Systematic Review of Published Interventions"
- Centers for Disease Control and Prevention: "How to Use Fruits and Vegetables to Help Manage Your Weight"
- Centers for Disease Control and Prevention: "Can Eating Fruits and Vegetables Help People to Manage Their Weight"
- U.S. Department of Agriculture: "Food Data Central: Broccoli"
- U.S. Department of Agriculture: "Food Data Central: Pasta"
- International Journal of Obesity: "Adaptive Thermogenesis in Humans"