by If you're asking which weight loss plan is best for you, the research does not name one winner for everyone. In head-to-head comparisons, weight loss diets have been shown to work about the same in terms of weight loss success, according to the article “The 7 Components of a Successful Weight Loss Plan” (published January 1, 2019). So the best plan is usually the one that fits your food preferences, your schedule and your health, and that you can keep doing for months.
How do I choose the best weight loss plan for me?
Start with a few honest questions. Your answers will narrow the options faster than any ranking.
- Can I eat this way for months? The 7 Components article says to look for a diet you enjoy, because cutting out everything you like can lead you to give up entirely.
- Does it leave room for my favorite foods? The same article suggests a smaller serving, a lower-calorie swap, or having a favorite food less often.
- Do I need someone checking in? Accountability matters. See the table below.
- Is the pace reasonable? The article advises aiming for about a pound per week.
- Do I have a health condition or take medicines that affect weight? If so, the answer goes to your clinician, not a diet book. More on that below.
| Program style | What the 7 Components article says |
|---|---|
| In-person or phone-based programs | Tend to lead to larger weight losses than online programs, because they have quite a bit of accountability and support. |
| Web-based or smartphone programs | Can help people with challenging or unpredictable schedules, especially if they include accountability and support. |
| Any program | Should keep providing accountability and support over the long term, which has been shown to help maintain initial success. |
The same article adds that “there is no perfect diet plan.” Pick the one that fits your life best and that keeps you going after small slips.
How fast can I lose weight without it backfiring?
Five kilograms is about 11 pounds. A pace of about one pound a week is what the 7 Components article recommends, and Healthline describes 1 to 2 pounds a week as sustainable weight loss. Losing 5 kg in a month is a faster pace than that range. Healthline says that losing 20 pounds in two weeks to a month “is rapid weight loss, which is not healthy and may be harder to achieve and maintain.”
| Pace or goal | What the source says |
|---|---|
| About 1 pound a week | The pace the 7 Components article says to aim for. |
| 1 to 2 pounds a week | Healthline's description of sustainable weight loss. |
| 5 kg (about 11 pounds) in a month | About 2.75 pounds a week on average, faster than the 1 to 2 pound range. |
| 20 pounds in 2 weeks to a month | Healthline calls this rapid weight loss that is not healthy and may be harder to achieve and maintain. |
A steadier pace over several months is the one these sources describe as the kind that lasts.
What simple habits help most when I'm starting?
Most people looking for quick results are really looking for habits they can keep. These are the ones the research here points to most clearly.
| Habit | What the research says |
|---|---|
| Drink a glass of water before meals | Healthline cites a meta-analysis of six studies that found a mean weight loss of 5.15% from increasing water intake. At least one of those studies tied it to replacing caloric drinks with water. |
| Cut back on sugary drinks | Healthline says avoiding sugary beverages can be an effective weight loss strategy, since they often make up a large share of calorie intake. |
| Eat protein at each meal | Healthline calls protein an important nutrient for losing weight. You can read more in protein for weight loss. |
| Combine movement types | Aerobic exercise and resistance training have been shown to help with weight loss over numerous studies, though exercise alone is less effective without the right dietary approach (Healthline). |
| Sleep 7 to 8 hours | Healthline gives 7 to 8 hours a night as the recommended amount for adults, and says lack of quality sleep is a strong risk factor for obesity. |
| Eat mindfully and keep a food diary | Healthline says numerous studies have found slower, more mindful eating can help you feel fuller sooner and promote long-term weight loss. |
For a walking routine, see how long to walk for weight loss. For more on what has worked for people, see most effective way to lose weight.
What should I expect in the first few weeks?
Expect the scale to be unpredictable. Healthline says it is “incredibly common for the scale not to budge for a few days (or weeks) at a time,” and that you can gain muscle and lose fat at the same time. Cleveland Clinic notes that most people gain and lose a little weight from day to day, and that these changes “tend to stay within a five-pound range.” Healthline also says it is often possible to lose weight fast at first, but few people keep losing more than 1 to 2 pounds per week. Its suggestion is to measure your waist circumference and body fat once a month instead of relying only on the scale.
A 2024 scoping review in the Journal of Health, Population and Nutrition found that results vary widely. It notes that “a wide degree of interindividual variability in weight loss is common in studies even after controlling for variables such as adherence, sex, physical activity and baseline weight.” It also lists previous weight loss attempts, sleep habits, meal timings and medications among factors that can change how much weight a person loses. The same review cites research showing that only about 20% of overweight people succeed at long-term weight loss, defined as losing at least 10% of initial body weight and keeping it off for a year. The 2024 scoping review on reasons for not losing weight is worth reading if a plan has stalled for you before.
How do the main plan types compare in studies?
Two small randomized trials are the most direct comparisons in the research here. Each tested a particular approach in a particular group, so neither ranks every plan.
In a randomized pilot study in Obesity Research (2002), 48 women who had had breast cancer, with a BMI of 30 to 44, were assigned to different approaches for 12 months. The 2002 weight-loss counseling trial on PubMed reports these results:
| Group | Average weight change at 12 months |
|---|---|
| Control | +0.85 kg (SD 6.0) |
| Weight Watchers program only | -2.6 kg (SD 5.9) |
| Individualized counseling only | -8.0 kg (SD 5.5) |
| Individualized counseling plus Weight Watchers | -9.4 kg (SD 8.6) |
The trial also found that most weight loss was achieved when counseling and Weight Watchers were combined, and that weight loss was significantly related to how often people attended meetings.
A 2013 randomized trial in the International Journal of Obesity compared the Medifast 5 & 1 Plan, a portion-controlled plan, with a reduced-energy, food-based diet. It enrolled 120 adults with obesity and followed them for 52 weeks. The 2013 Medifast 5 & 1 trial on PubMed reports:
| Group | Average weight loss at 26 weeks | Average weight loss at 52 weeks |
|---|---|---|
| Medifast 5 & 1 Plan | 7.5 kg | 4.7 kg |
| Food-based reduced-energy diet | 3.8 kg | 1.9 kg |
The authors concluded that the portion-controlled plan produced significantly greater reductions in body weight and fat than the food-based diet over one year. The trial compared one commercial plan with one food-based diet, so it does not tell you how any other plan would perform for you.
A 2018 trial cited by Healthline found little difference between a nutrient-dense, low-fat diet and a nutrient-dense, low-carb diet. Healthline adds that the effect of cutting carbs seems more pronounced in the first 6 to 12 months than in the long term. Finding a meal plan you can enjoy long term is key.
Where do prescription medicines fit in?
Medicines are a clinician decision, and the information below is meant to help you prepare questions. Cleveland Clinic says providers prescribe GLP-1 agonists for two conditions, type 2 diabetes and obesity, and that the FDA currently approves semaglutide and high-dose liraglutide to help treat obesity. Harvard Health's April 14, 2025 guide to how GLP-1s work also lists tirzepatide (Zepbound) as FDA-approved for weight loss.
Harvard Health says that “in some studies, participants using GLP-1s have lost an average of 10% to 15% of their body weight over a year,” and that “the most effective GLP-1 medications can lead to weight loss of over 20% of body weight.” Those are study averages, not guarantees for you.
| Side effect or risk | What Harvard Health says |
|---|---|
| Pancreatitis | Some studies suggest a possible link, though the risk appears to be low. |
| Gallbladder problems | Some people develop gallstones or gallbladder inflammation while taking GLP-1s. |
| Thyroid tumors | Animal studies raised concerns, but ongoing surveillance has not shown that this applies to humans. |
| Muscle loss | Rapid weight loss from GLP-1s may lead to a decrease in muscle mass. Harvard Health notes your doctor may advise more protein to reduce that risk. |
| Pregnancy and breastfeeding | These medications are not considered safe for use during pregnancy or breastfeeding. |
The National Academy of Medicine's GLP-1 health basics says that “it is estimated that many as 50% to 75% of people who take a GLP-1 discontinue it within a year.” It also says that after stopping, “many people are likely to regain most of the weight they lost.” Ask your clinician how they would handle that before you start.
The same National Academy page says the FDA “has not assessed” compounded versions “for safety, effectiveness, or quality.” Harvard Health advises to beware of compounded GLP-1 drugs. For more on how to think about cost and safety in this category, see safest weight-loss drug.
Questions to bring to a clinician:
- Is a medicine appropriate for my health history and the medicines I already take?
- Which side effects should I watch for, and what should I do if they start?
- How would we handle weight regain if I stop?
- What eating and protein plan do you recommend alongside it?
When should I see a clinician before I start?
Cleveland Clinic says unexplained weight loss is concerning if you lose “more than 5% of your body weight or 10 pounds over six to 12 months, especially if you're over age 65.” Its advice is to always see a healthcare provider if you lose weight without trying, and not to treat it at home.
WebMD's list of reasons you can't lose weight names heart disease, hormonal disorders and sleep disorders such as sleep apnea. It also names medicines used for allergies, birth control, depression, diabetes, epilepsy, high blood pressure, bipolar disorder and schizophrenia. If one of these applies and weight is a problem, WebMD advises talking to your doctor, who can review your treatment plan. Do not change any medicine on your own. Ask your prescriber first.
If you find that food feels out of control, Healthline says to speak to your doctor about binge eating disorder.
What should my first month look like?
A realistic first step is small and repeatable. Use this checklist for the first month, then review it.
- Write down your starting weight and waist size today.
- Keep a food diary for one week, noting what and when you eat.
- Drink a glass of water before meals.
- Include protein at each meal.
- Pick one walking or strength routine you can repeat, and build from it.
- Aim for 7 to 8 hours of sleep a night.
- Check your waist size and body fat once a month instead of judging by the scale each day.
- If you have a health condition or take medicines, write down two questions for your clinician.
In the first weeks, expect some scale ups and downs and a slower pace after the early changes. That is normal in the research and does not mean the plan has failed.
Before you choose, what can't the research tell you?
- The studies above can't rank plans for your age, sex or health, and each trial tested one approach in one group.
- Trial results are averages. Your results will vary, as the 2024 scoping review describes.
- A plan that fits you is the one you can keep. Choose the approach you can sustain and check any change with your clinician.
By the New Life Wellness Guide Editorial Team
This article is for general information purposes only and does not constitute medical advice. Consult your doctor or qualified healthcare provider before making changes to your health routine.