If you’re searching for the best diets to lose weight for September 2025, this month features my list of what’s trending for the first month of fall along celebrity-inspired plans that are shaping how people approach weight loss.
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Ah September!
With my September 4th birthday behind me, I’m feeling a renewed determination to finally shed those last stubborn 20 pounds. There’s something about a birthday that makes you look both backward and forward—and for me, that means re-evaluating my health and considering different diets once again.
Summer indulgences have passed, and the fall season is the perfect time for a reset. Just as the leaves change, it feels like the right moment to change old patterns and build a more balanced diet filled with whole foods and healthy fats.
That’s why I’ve decided to launch a new series: each month, I’ll break down the best diets making waves and give you an honest look at whether they might be right for you.
Nutrition experts agree that while some are science-backed diets, others fall more into the category of fad diets, making it essential to separate long term strategies from short term fixes.
So let’s get started with this month’s list of the best diets to lose weight for September.
#1 – Intermittent Fasting
What Is It: First on my list of the best diets to lose weight for September is Intermittent fasting (IF). IF involves cycling between periods of eating and fasting—popular methods include the 16:8 (fast for 16 hours, eat within an 8-hour window) and alternate-day fasting. According to Johns Hopkins Medicine, fasting helps trigger metabolic switching that encourages fat burning and may improve body weight control.
The Good: It’s simple to follow, doesn’t require calorie counting, and can be adapted to your daily diet. Many people report steady energy and fewer cravings once their bodies adjust. A review in the New England Journal of Medicine found numerous studies linking intermittent fasting to reduced inflammation, improved blood sugar control, and long term health benefits.
The Bad: The initial adjustment period can be tough, with headaches, hunger pangs, and irritability. Social situations, like dinners out, can feel restrictive. Experts in the Times of India caution that people with diabetes or certain medical conditions should avoid it.
Made Famous By: Celebrities like Terry Crews and Hugh Jackman helped showcase its benefits on social media, inspiring many to try it as a new diet trend.
Recommendation: A strong option for disciplined people who want flexibility without overhauling their food groups. Best for those who can handle short term hunger discomfort and thrive on routine. Not suitable for individuals with chronic diseases or health risks requiring regular calorie intake.
#2 – Keto Diet
What Is It: The ketogenic diet is a very low-carbohydrate diet, high in animal fats and protein, designed to push your body into ketosis, a metabolic state where fat is burned for fuel instead of glucose. According to Harvard Health, the keto diet remains one of the best low-carb diets in the United States.
The Good: Keto can bring about rapid weight loss in the first few weeks, largely due to reduced calorie intake, water loss, and fat metabolism. Many dieters report reduced appetite and better mental focus. Experts at Harvard note potential benefits for people managing blood sugar issues.
The Bad: It’s highly restrictive and eliminates essential nutrients from whole grains, fresh fruits, and dairy products. Some people experience the “keto flu” (headaches, fatigue, nausea) during adaptation.
Made Famous By: Kim Kardashian reportedly used keto to lose post-pregnancy body weight, while Halle Berry has promoted it for managing medical conditions like diabetes.
Recommendation: Suitable for people who love animal protein and fatty acids but can commit to strict carb avoidance. Not recommended if you value a balanced diet with plant-based foods and fresh fruits. A good idea for short term results, but not a healthy diet for life.
#3 – Mediterranean Diet
What Is It: The Mediterranean diet emphasizes olive oil, vegetables, legumes, fatty fish, nuts, fresh fruits, and whole grains—modeled after traditional eating in the Mediterranean region. According to the Mayo Clinic, numerous studies show this eating pattern supports heart health and overall health.
The Good: Backed by clinical trials showing benefits for cardiovascular disease prevention and reduced risk of heart disease. It promotes healthy fats like monounsaturated fats from olive oil and omega-3 fatty acids from fish.
The Bad: Because it’s not strictly focused on calorie intake, body weight changes may be slower compared to more restrictive diet plans. Access to high-quality vegetable oils, fatty fish, and fresh produce may also be expensive. For those expecting rapid weight loss, it can feel underwhelming.
Made Famous By: U.S. News & World Report has consistently ranked it as the best overall diet. It was also popularized by Dr. Ancel Keys’ research along the Mediterranean Sea.
Recommendation: Among the best diets to lose weight for September, this plan is ideal for people seeking a balanced diet rich in whole foods. It is especially beneficial for lowering cholesterol levels, supporting brain function, and protecting against chronic diseases. Less suitable if you demand quick results or want strict rules.
#4 – DASH Diet
What Is It: The Dietary Approaches to Stop Hypertension (DASH) diet was developed to lower high blood pressure and emphasizes fresh fruits, vegetables, lean proteins, and low-fat dairy products. According to the Cleveland Clinic, the DASH diet is backed by scientific evidence showing reduced risk factors for cardiovascular disease.
Here’s a nice overview of the DASH Diet that I found out on YouTube from registered dietician Tracy Lockwood Beckerman:
The Good: Highly respected and evidence-based, with strong clinical trials supporting its effectiveness for reducing blood pressure and improving overall health. It is also a balanced diet that includes whole grains, fresh fruits, and vegetable oils.
The Bad: Weight loss is a side effect rather than the primary goal. Sodium restrictions may be challenging for those who eat processed foods regularly. It also demands long term planning and careful calorie intake tracking.
Made Famous By: Promoted by the National Institutes of Health and endorsed by the American Heart Association, it’s frequently highlighted as a best diets category winner.
Recommendation: Excellent for people with risk of heart disease or high blood pressure. A healthy diet option recommended by registered dietitians and health care providers. Less appealing for those chasing trendy diets or rapid weight loss.
#5 – Paleo Diet
What Is It: The Paleo diet, or Paleolithic era eating style, is one of the best diets to lose weight for September because focuses on lean meats, red meat, fresh fruits, vegetables, nuts, and seeds while excluding dairy products, legumes, and grains. According to Harvard Health, this eating plan is built on the idea that our bodies thrive on whole foods similar to those eaten by our ancestors.
The Good: Encourages nutrient-dense, science-backed diets by eliminating processed foods and focusing on essential nutrients. Rich in animal protein and healthy foods, it often improves digestion, energy, and body weight management.
The Bad: Cutting out food groups like grains and dairy products may cause nutrient gaps. It can also be costly to maintain high-quality animal fats and meats. Critics argue it oversimplifies human nutrition and ignores modern scientific evidence.
Made Famous By: Popularized through CrossFit communities and promoted by Dr. Loren Cordain as a new diet for modern times. Social media helped elevate it into the spotlight as one of the best diets.
Recommendation: As one of the best diets to lose weight for September, it works well for meat lovers willing to give up dairy and grains. Good for short term fat loss, but less ideal as a long term balanced diet. Seek guidance from a registered dietitian if you have medical conditions.
#6 – WeightWatchers (WW)
What Is It: Comoing in next on my list of the best diets to lose weight for September is an old fan favorite. WeightWatchers uses a points-based system to assign values to foods, helping participants track and control calorie intake while still eating what they like. According to WeightWatchers, the modern plan emphasizes healthy foods, plant-based foods, and flexibility.
WW has a nice app that Nikki Gets Fit explains how to use in this YouTube tutorial:
The Good: A proven track record supported by numerous studies and millions of success stories. It promotes whole foods, fresh fruits, and healthy fats while teaching portion control. Group coaching helps users manage risk factors and build long term habits.
The Bad: The program requires ongoing tracking, which can feel tedious. Membership fees may be a barrier. Some nutrition experts warn that regaining body weight is common if accountability is lost.
Made Famous By: Oprah Winfrey’s investment and endorsement gave WeightWatchers mainstream visibility in the United States.
Recommendation: A healthy diet plan for those who need accountability, structure, and social reinforcement. It’s especially good for people managing medical conditions or chronic diseases who need support. Less ideal for those looking for a free, self-directed eating style.
#7 – Flexitarian Diet
What Is It: The Flexitarian diet is primarily plant-based but allows occasional animal products. According to WebMD, it emphasizes plant-based foods, whole grains, and fresh fruits while permitting flexibility with meat and dairy products.
The Good: Encourages plant-based diet diversity, supports overall health, and lowers the risk of heart disease. It is more sustainable than strict vegetarian diets while still cutting down on red meat consumption.
The Bad: Because it’s less structured, calorie intake can creep up if you’re not mindful. It may not deliver rapid weight loss like more restrictive low-carbohydrate diets. Some find it too vague compared to other diet plans.
Made Famous By: Dietitian Dawn Jackson Blatner, who introduced it as a good idea for balancing healthy foods with flexibility.
Recommendation: Among the best diets to lose weight for September, this is perfect for people wanting to reduce animal protein without fully committing to vegetarian diets. It’s a good long term eating plan with plenty of health benefits.
#8 – Atkins Diet
What Is It: The Atkins diet is a classic low-carb diet developed in the United States. According to the Atkins website, it restricts carbs to control body weight and blood sugar levels while allowing animal protein and healthy fats.
The Good: One of the most science-backed diets in terms of low-carb weight loss. It has clinical trials supporting improvements in cholesterol levels and risk factors for metabolic syndrome.
The Bad: Considered one of the original fad diets by some, as it encourages high intake of red meat and animal fats. Long term health risks may arise if vegetable oils, fresh fruits, and whole foods are neglected.
Made Famous By: Dr. Robert Atkins, who launched the low-carbohydrate diet trend decades ago. It remains one of the best known diet plans globally.
Recommendation: As one of the best diets to lose weight for September, Atkins can be effective short term for rapid weight loss and body weight reduction. Not ideal as a lifelong healthy diet, but useful if monitored by a health care provider.
#9 – Vegan Diet
What Is It: The Vegan diet excludes all animal products, focusing on plant-based foods like legumes, grains, vegetables, fruits, and nuts. According to the NHS, it can deliver numerous health benefits if carefully planned.
The Good: Promotes overall health, lowers the risk of cardiovascular disease, and reduces health risks linked to high cholesterol. A well-designed vegan diet provides essential nutrients and supports long term weight management.
The Bad: Eliminating animal protein entirely can create nutrient gaps in vitamin B12, iron, and calcium. Plant-based diets may require supplementation to ensure adequate essential nutrients.
Made Famous By: Celebrities like Billie Eilish elevated it on social media, highlighting ethical and environmental motivations.
Recommendation: This made my list of the the best diets to lose weight for September, as vegan eating patterns work well for those motivated by ethics and sustainability. A good idea for lowering risk of heart disease, but it requires careful planning with a registered dietitian.
#10 – MIND Diet
What Is It: The MIND diet is a hybrid of the Mediterranean diet and DASH stands for Dietary Approaches to Stop Hypertension. According to the Alzheimer’s Association, it focuses on plant-based foods, whole grains, leafy greens, and healthy fats to reduce neurodegenerative delay.
The Good: Clinical trials show it supports brain health and may protect against chronic diseases. It emphasizes fresh fruits, vegetable oils, and whole foods while limiting animal fats and red meat.
The Bad: Like other balanced diets, it produces gradual changes in body weight. Some find it restrictive in terms of animal protein and dairy products.
Made Famous By: Researchers studying the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND). It has been praised by the American Heart Association among others.
Recommendation: The MIND Diet it is ideal for people prioritizing brain and heart health. A smart long term eating style but less appealing if you want trendy diets or rapid results.
#11 – Gluten-Free Diet
What Is It: Rounding out my list of the best diets to lose weight for September is another great diet specifc to those with gluten issues.The gluten-free diet eliminates wheat, barley, and rye to remove gluten proteins. According to the Celiac Disease Foundation, it is essential for those with celiac disease or gluten sensitivity. Despite being a medical necessity, it has become one of the trendy diets in the United States.
The Good: Eliminates digestive symptoms for those with celiac disease or irritable bowel syndrome. It promotes whole foods like fresh fruits, vegetables, and lean proteins. Clinical trials show it improves overall health in people with gluten-related conditions.
The Bad: For those without medical conditions, it may unnecessarily cut out whole grains and essential nutrients. It can also lead to higher calorie intake if replaced with processed gluten-free foods. Here are some common concerns about the Gluten-Free diet as explained by Dr. Eric Berg DC.
Made Famous By: Many celebrities on social media promoted it as a new diet fad, even without gluten intolerance.
Recommendation: It’s crucial for people with celiac disease or gluten sensitivity. Not a good idea for the general population unless medically necessary, as it can create avoidable health risks.
Best Diets to Lose Weight for September: Final Thoughts
The best diets to lose weight for September range from science-backed diets like the Mediterranean diet and DASH diet to trendy diets such as the Atkins diet and gluten-free diet. Social media, celebrity endorsements, and U.S. News & World Report rankings all influence which diets gain traction.
While each eating plan offers unique health benefits, nutrition experts caution that the best diets are the ones sustainable for the long term.
Numerous studies highlight that whole foods, plant-based foods, healthy fats, and fresh fruits form the foundation of a balanced diet. Whether you choose intermittent fasting, the paleo diet, or the MIND diet, focus on essential nutrients, overall health, and reducing risk factors like high cholesterol and cardiovascular disease. And always consult a registered dietitian or health care provider before committing to a new diet.
Want to learn about more diets, check out this monster blog post I wrote on the 101 best Diets Right Now.
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