Health Tips: How the 80/20 rule helped this woman lose weight

Try this mental shift to eat better and lose weight. A diet doesn't need to be 100 percent healthy to be healthy, according to Work Week Lunch founder Talia Koren. The blogger lost 10 pounds following the 80/20 rule, which involves focusing on eating healthy foods 80 percent of the time, and less healthy foods the remaining 20 percent.

"I wasn't restraining myself and I think that's the key to what makes it work," Koren tells NBC News Better. "You can have what you want, but you have to have more of the healthy stuff."

The 25-year-old says she put on a few extra pounds in college. Her eating habits worsened after she started working for a busy New York City media company, where "pizza days" and free bagels were the norm. Shedding the weight seemed impossible.

"When you're not eating well, your energy levels are affected, and that's what I found," Koren said. "I was really sluggish. I didn't like the way my clothes fit. I just didn't feel good about myself."

Koren tried numerous diet fads, none of which seemed to help her lose weight. Exercise didn't seem to help either. In 2015, while researching online, she learned about the 80/20 rule and decided to try it.

Daily Vs. Weekly Approach

Koren approached the 80/20 rule using what she calls the "week-long" approach. She eats about 21 meals in a week, 80 percent of which make up about 17 meals. She prefers this to the "day-long" approach, which means 80 percent of her daily meals are healthy.

"If 20 percent [of what you eat] is sweet potato fries every day, that's going to add up," she explains.

The week-long approach, however, forces her to have more self-restraint. While about 17 of her meals are healthy during the week, just four are less healthy.

What to eat and not eat

Koren began cooking her meals at home. Her healthy meals consist of whole grains, lean proteins, fruits and vegetables and nutrient dense carbs.

For example:

• Breakfast: Two slices of wheat toast with peanut butter and blueberries
  
• Mid-morning snack: A piece of fruit (whole apple, whole plum, whole peach)
  
• Lunch: Salmon, sweet potatoes, and broccoli
  
• Mid-afternoon snack: Sliced pepper with hummus, or a handful of almonds with dates
  
• Dinner: Scrambled eggs with veggies

She decided to reserve her less healthy meals for when she eats out with friends. But she's careful not to pick menu items that are too unhealthy.

"I love Mediterranean food," she says. "So I would get falafel, which is fried, and maybe some cole slaw — there would be mayo in there — that type of thing, where it's not totally unhealthy but not super strict either."

You should never use your 20 percent "less healthy" meal allowance as an excuse to binge eat, she warns.

"That doesn't mean you're going to an extreme opposite like you're just going to eat pizza 20 percent of the time," she says. "It just means caring a little less."

How to use the 80/20 rule

• Will it be weekly or daily? On the week-long approach, 80 percent of your weekly meals are healthy. The daily approach, on the other hand, means 80 percent of your daily meals are healthy. Koren found the weekly approach more effective, since it forced her to eat more healthy meals.
  
• Educate yourself. Healthy meals should consist of whole grains, lean proteins, fruits and vegetables and nutrient dense carbs. Your less healthy meals should be an opportunity for you to eat what you enjoy, but not an excuse to binge eat junk food.
  
• Invest time in meal prep. Meal prepping is an important way to ensure you always have healthy options available, and will prevent you from making unhealthy excuses when hungry.
  
• Focus on the small stuff. When you focus on changing your eating habits and lifestyle, your body and energy levels will change too.