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I Lost 15 Pounds in 6 Weeks by Doing These 3 Things

Here is how one woman lost 2.5 pounds a week.
FACT CHECKED BY Christopher Roback

Isis Kellier is a diet and fitness influencer who regularly shares videos on her channel about how she lost weight fast and got into the best shape of her life. In one TikTok video she reveals how she dropped an average of 2.5 pounds a week by making a few simple changes to her diet and fitness routine. "How I lost 15 pounds in six weeks," she starts the clip, going on to reveal her secrets. We also asked The Diet Diva, Tara Collingwood, MS, RDN, CSSD, LD/N, ACSM-CPT, a Board Certified Sports Dietitian, to weigh in on her tactics. 


Intermittent Fasting


The first thing Isis did? Intermittent fasting, or "OMAD," she reveals, which stands for "one meal a day. "The Lightly intermittent fasting app helps to keep everything on track," she added. In another video she details what she eats in a day, starting at 2:00 pm with two glasses of green juice followed by a bowl of fruit. For her main meal of the day, "dinner," she eats at 4:00 pm and enjoys spicy vodka pasta with a grilled chicken breast on top. At 5:30 pm she drinks two Premiere Protein shakes.

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Expert Weighs in on OMAD


"It sounds like she is only eating in a less than 4 hour window which is a very small eating window," Collingwood notes. "I like that she has antioxidant rich green juice and fruit, but that is not really a ton of produce or fiber. When you eat most of your produce as juice, you are missing out on a lot of fiber which is really important for gut health and keeping the microbiome in check." As for protein, she is likely meeting her requirements with the grilled chicken, "not sure size but let's assume 4 oz = 28 grams of protein and two premier protein shakes at 30 grams each gives her another 60 grams to push her over 80 grams for the day," she notes. "However, two highly processed protein shakes are not really providing the quality of food we like for overall good health. They do have a lot of vitamins and minerals added to them, which she needs because she is not eating very many calories or a variety of foods." She is happy to see some carbs in the pasta, "but vodka sauce does not really provide much nutritional value," she adds. " Marinara would be much better with the antioxidants and nutrients in tomatoes." Overall Collingwood is concerned about her low calorie intake. "Again, I don't have exact portion sizes but I estimate this to be about 1000-1200 calories."  

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30-60 Minutes of Cardio Daily


Next up? "30 to 60 minutes of cardio daily," she reveals. In the other video she reveals that she does "fasted cardio" in the morning prior to her first meal. 


Expert Weighs in On Her Workout


According to Collingwood, 30 to 60 minutes of cardio "is great," she says. However, "if she is doing this in the morning and not getting any calories until 2 PM (and that is very few with the green juice and fruit and no protein) she is leaving her body susceptible to poor recovery, injury risk, dehydration, and low energy," she points out. 

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Calorie Deficit


Her final secret to losing 15 pounds in six weeks? Maintaining a "caloric deficit," she says. The basic math of calories in vs calories out is caloric deficit which is necessary to lose weight, Collingwood agrees. "But you can create a caloric deficit in many other more healthy ways that include fueling the body in more regular intervals, feeding more nutritious foods, and having more balance."


Bottom Line: Is a 15-Pound Weight Loss in 6 Weeks Realistic?


Collingwood and most experts agree that a healthy weight loss rate is typically one to two pounds per week. "15 pounds in 6 weeks is a bit higher than that," Collingwood points out. "It all depends on how much weight someone has to lose.  If you have 100 pounds you lose, it will come off faster initially. If you only have 15 pounds to lose, the weight will come off more slowly.

In general, the faster it comes off, the more likely there is a higher proportion of muscle coming off vs a majority of fat tissue."

@isiskellier I mainly did OMAD. I would recommend trying Intermittent fasting first and see if it's for you. Using the @Litely_App can help you stay on track and also track your progress as well. #litelyapp #intermittentfasting #weightloss #20lbsdown ♬ TELEKINESIS (feat. SZA & Future) – Travis Scott

💪🔥Body Booster: Intermittent fasting is a form of dieting that works for some people. Oftentimes if you are eating in a short window, you will consume less calories. 

Leah Groth
Leah Groth has decades of experience covering all things health, wellness and fitness related. Read more