Is Eating 1,400 Calories a Day for Weight Loss a Good Idea?

Depending on how many calories you currently eat and how active you are, switching to a 1,400-calorie daily diet may cause you to lose more than a pound per week.

However, a 1,400-calorie diet may not be safe for you if you're very active. It's also not recommended if you're young (between the ages of 9 and 18) and haven't finished growing and developing. In fact, the American Heart Association recommends anywhere from 1,600 to 1,800 calories for children ages 9 to 13, and about 1,800 to 2,200 for those ages 14 to 18.

And regardless of activity levels, 1,400 calories a day is not sufficient for many adults. According to Harvard Health Publishing, the minimum daily caloric intake recommended for people assigned male at birth (AMAB) is 1,500. While the minimum for people assigned female at birth (AFAB) is 1,200 calories per day, that number is still very low and not necessarily healthy for many people AFAB.

For most people, 1,400 calories a day is not enough. This amount is simply too low and not sustainable.

Following a low-calorie diet can cause the following side effects, according to the Academy of Nutrition and Dietetics:

• Osteoporosis (thinning of the bones)
• Slowed metabolism (which may lead to weight gain)
• Sluggishness and fatigue
• Sensitivity to the cold
• Constipation
• Brain fog
• Gallstones
• Thinning hair
• Damaged tooth enamel
• Weakness

It's recommended to stay between 2,400 and 2,800 calories for people AMAB and 1,800 to 2,200 for people AFAB, according to the 2020-2025 Dietary Guidelines for Americans. (These ranges are for those who are moderately active. Caloric needs will vary depending on your level of activity.)

But, "it's hard to pinpoint one number that would apply to everyone's caloric and nutritional needs," says Mir Ali, MD, a bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center.

"Your height, weight, age, activity level and whether you have underlying medical conditions will determine your baseline requirements per day. We want to be realistic," he adds.

If your doctor has signed off on this eating plan, there are some steps you can take to make it doable.

Your 1,400-calorie diet plan should consist of three meals that are roughly 400 calories and two snacks that are 100 calories each. Planning how much you're going to eat at each meal and snack and eating regularly throughout the day can help control hunger and make it easier to stick with your plan.

Formally named the Diabetes Plate Method, this way of eating requires half of your plate to be non-starchy vegetables, one-quarter carbohydrates and one-quarter protein, according to the American Diabetes Association.

This can help take the guesswork out of meal planning and remembering what you ate once you go to track your calories.

If you find 1,400 calories is not satisfying your hunger, try including plenty of high-fiber foods in your meal plan, like whole-grain pasta, brown rice, leafy greens and fruit. Fiber takes longer to digest, helping you feel fuller longer.

Dr. Ali says you can think of carb as fuel and fat as reserves. "If you take away the fuel, your body is forced to use reserves for energy," he says. This is how you can burn excess fat.

"Sugars and concentrated sweets prevent weight loss and force the body to create insulin, one of the elements the body signals to hold onto and use as energy," Dr. Ali says.

Lean protein sources like fish, turkey, chicken and eggs also take longer to digest, so they can keep you satisfied for longer. Eating lean protein can also help you preserve lean body mass and store less body fat, according to the Cleveland Clinic.

Your basal metabolic rate is the number of calories you would burn on a daily basis if you were completely inactive. It's a measure that's dependent upon your sex, age and overall body size.

There are apps and online calculators you can use to determine your basal metabolic rate, Dr. Ali says.

When cutting calories, it is important to consider your basal metabolic rate in order to still properly nourish your body. Below are some basal metabolic rate examples from the BMR calculator at Health Status, a health assessment website:

Your activity level also determines the amount of weight you can lose when following a 1,400-calorie diet. If you're very active, you might burn up to 500 calories or more with exercise every day, which could help you lose up to an extra pound per week.

However, even if your lifestyle is sedentary, reducing your daily calories will help you to slim down at a more gradual pace.

The amount of weight you lose can be expressed in a calorie deficit that you build up through cutting calories and working out. You need to reach a deficit of 3,500 to lose each pound. That means that if your basal metabolic rate is around 2,000 and you begin eating just 1,400 calories per day, you'll build up a weekly deficit of 4,200 calories, or enough to lose about 1.2 pounds per week, per the Cleveland Clinic.

If you also burn about 300 calories per day through exercise, you'll lose closer to 2 pounds per week. To get an accurate idea of how many calories you're taking in, use an online calorie counter and record everything you eat and drink.

"[Tracking calories] is a difficult thing to do on a regular basis, but it's a good place to start to get a sense of how much you are taking in," Dr. Ali says.

This meal plan can give you an idea of what it's like to eat 1,400 calories in a day for weight loss. Each meal will be around 400 calories, and snacks around 100 calories:

Choose one of the following:

• Cranberry Crumble Oatmeal (409 calories) and coffee with 1 tablespoon of whole milk (10 calories)
• Protein Veggie Omelet (290 calories) with 1 slice whole-wheat dry toast (81.5 calories) and 1/2 cup of strawberries (32 calories)
• Almond Butter & Blueberry Smash Smoothie (or another smoothie recipe) (238 calories) and two large hard-boiled eggs (155 calories)

Opt for one of these:

• Champagne Cobb-Style Salad (256 calories) and 3 oz skinless chicken breast (120 calories)
• Lentil Walnut Soup and Side Salad (319 calories) and 1 cup of blueberries (80 calories)
• Smoked Salmon and Caper Sandwich (or other sandwich recipes) (279 calories) and 4 cups of plain, air-popped popcorn (100 calories) and 1/2 cup of raw baby carrots (41 calories)

Pick one of these options:

• Sweet Potato Nachos (245 calories) and guacamole with a secret ingredient (88 calories)
• Simple Turkey Salsa Chili (339 calories) and 1 slice of whole-wheat bread (81.5 calories)
• Whole Grain Pasta Carbonara (293 calories) and Caesar-style kale salad (91 calories)

Choose two of these snacks per day, each of which is about 100 calories:

• 6 ounces of nonfat plain Greek yogurt
• 10 pecan halves
• 1/2 cup of whole-grain, unsweetened cereal with 1/2 cup of nonfat milk
• 2 cups of mixed greens topped with 2 tablespoons of low-fat salad dressing
• A small apple with 1 teaspoon of peanut butter
• 4 cups of plain, air-popped popcorn
• 1 1/2 cups of cubed cantaloupe

Always get your doctor's approval before starting a low-calorie diet. If you don't follow an eating plan that is balanced and varied, you could develop nutritional deficiencies, experience fatigue or develop other health issues.

"There is no one set formula for everyone when it comes to losing weight," Dr. Ali says. "If you are having trouble, start at your primary care doctor to rule out medical concerns." From there, you could be referred to a specialist.

A 1,400-calorie diet is not safe if you are still young and growing, if you're very active or have other underlying medical conditions.

Ultimately, a medically supervised, very low-calorie diet is only recommended to those with particular health issues or those who have obesity.