With so many diets out there, it can be difficult to sift through them all to choose one the right one for you. A 50-30-20 diet, also called IIFYM or flexible dieting, is a popular option because instead of restricting certain foods, it focuses on counting the total number of macronutrients you eat.
This approach allows more flexibility in your diet and gives you the freedom to choose the foods you like. The idea is that, as long as you're staying within the guidelines of 50-30-20, weight loss will come naturally.
However, there isn't one 50-30-20 meal plan that's right for everyone across the board. Some people prefer to get 50 percent of their calories from carbohydrates, while others get half of their calories from fat or protein. Once you make that choice, you can design your meal plan around healthy, nutrient-dense foods.
Figure Out Your Calorie Needs
IIFYM is an acronym that stands for "If It Fits Your Macros." Also called "flexible dieting," IIFYM is not a rigid diet; it's a dietary guideline that allows you to eat whatever you want, as long as you're staying within your macronutrient, or macro, needs. With IIFYM, you calculate how many calories you need and then you use that number to determine which percentage of calories should come from each of the macronutrients — carbohydrates, protein and fat.
The underlying theory of IIFYM is that it doesn't matter what you eat, as long as you're not eating too many calories and your macronutrients stay within a personalized ratio. One study that was published in Eating Behaviors in January 2013, reported that people who follow diets that allow greater variability in food choices, like IIFYM, are more likely to stick to the diet and maintain weight loss over time.
When designing a diet around macronutrients, the first thing you need to do is figure out your exact calorie needs. This will depend on your age, your sex, your current height and weight and your activity level. The amount of calories you need to eat also depends on what your goals are. If you're trying to lose weight, you'll need fewer calories than if you're trying to build muscle, for example.
After you decide what your goals are, you can use LIVESTRONG.com's Calorie Counter to quickly generate a specific number for you. Once you have that number, you can use it to calculate your 50-30-20 macros.
Your 50-30-20 Macros
A typical 50-30-20 diet is broken down into 50 percent carbohydrates, 30 percent protein and 20 percent fat, but if your goal is to improve your health while you lose weight, you may want to switch those numbers around.
An October 2015 PLOS One study compared the effects of low-carb diets and low-fat diets on weight loss in overweight and obese participants. While both groups lost weight, weight loss in the low-carb diet group was significantly greater, and participants reaped the added benefit of improved cardiovascular factors, like lower LDL, or "bad," cholesterol and higher HDL, or "good," cholesterol.
To add to that, a July 2013 Diabetes Care study compared restricted calorie high-protein diets (40 percent of calories from protein and 40 percent of calories from fat) to restricted calorie high-carbohydrate diets (55 percent of calories from carbohydrates) and found that after six months, the high-protein diets improved insulin sensitivity, lowered inflammation and decreased oxidative stress to a greater degree than the high-carbohydrate diets.
Researchers from another study that was published in the American Journal of Clinical Nutrition in October 2015 compared the effects of a high-carbohydrate diet, which provided 53 percent of calories from carbs, and a low-carbohydrate diet, which provided 53 percent of calories from fats, on obese participants with diabetes.
While participants in both groups were able to successfully lose weight and lower their blood sugar levels, the group following the low-carbohydrate diet ended up with better cholesterol and triglyceride numbers and were able to control their blood sugar better.
One of the biggest benefits of a 50-30-20 diet is that you can design it around your goals and personal preferences. Whether you decide to get 50 percent of your calories from carbohydrates, 30 percent from protein and 20 percent from fat or you prefer to take a low-carb, more keto-style approach and get 50 percent of your calories from fat, 30 percent from protein and 20 percent from carbohydrates, there are some basic guidelines you can follow to develop your menu plan.
50-30-20 Diet Guidelines
But even though a 50-30-20 diet gives you some more flexibility with your food choices, you should still do your best to design a healthy menu plan. Doughnuts and cookies might fit into your 50-30-20 macros, but that doesn't mean it's a good idea to work them into your diet every day.
Nutrition statistics show that people who focus only on macronutrients eat less than the recommended amount of micronutrients (vitamins and minerals) for the day, according to a September 2018 International Journal of Sport Nutrition and Exercise Metabolism study. This effect was also seen with rigid dieters, so it's not an isolated IIFYM concern, but it's something to think about when developing your 50-30-20 recipes and meal plans.
To make sure you're optimizing your micronutrient intake, always fill at least half your plate with nonstarchy vegetables. Focus on variety with your vegetables too. Instead of eating broccoli every day, eat lots of different kinds (and different colors) of vegetables to make sure you're getting a variety of vitamins and minerals.
It's also a good idea to add lean protein to every meal. You can choose from lean beef, pork, chicken, eggs, nuts or beans. The USDA recommends making seafood your protein choice at least twice a week. Aside from that, you can optimize the amount of vitamins and minerals you're getting by focusing on eating lots of nutrient-dense foods, which are foods that give you a lot of nutrients for a relatively low number of calories.
Harvard Health Publishing has published a list of nutrient-dense foods to get you started:
- Swiss chard
- Collard and mustard greens
- Brussels sprouts
- Bell peppers
- Baked and sweet potatoes
- Flax seeds, chia seeds and pumpkin seeds
- Eating Behaviors: "Cognitive and Weight-Related Correlates of Flexible and Rigid Restrained Eating Behaviour"
- International Journal of Sport Nutrition and Exercise Metabolism: "A Comparison of the Nutrient Intakes of Macronutrient-Based Dieting and Strict Dieting Bodybuilders."
- Diabetes Care: "Effects of High-Protein Versus High-Carbohydrate Diets on Markers of β-Cell Function, Oxidative Stress, Lipid Peroxidation, Proinflammatory Cytokines, and Adipokines in Obese, Premenopausal Women Without Diabetes"
- American Journal of Clinical Nutrition: "Comparison of Low- and High-Carbohydrate Diets for Type 2 Diabetes Management: A Randomized Trial"
- PLOS One: "Dietary Intervention for Overweight and Obese Adults: Comparison of Low-Carbohydrate and Low-Fat Diets. A Meta-Analysis"
- USDA ChooseMyPlate: "10 Tips: Build a Healthy Meal"
- Harvard Health Publishing: "Getting Your Vitamins and Minerals Through Diet"