Before you pay
How to spot a safe weight-loss program
Before you hand over your card details, spend ten minutes with this checklist. It will help you tell a program that can actually help you from one that mainly wants your money.
A safe program aims for about 0.5-1 kg (1-2 lb) a week after the first few weeks, uses ordinary food rather than required supplements, gives you ongoing support and has a plan for keeping the weight off. It's also upfront about cost, who designed it and what results are typical.
Red flags and green flags
If you spot two or more red flags, walk away.
| Red flag | Green flag |
|---|---|
| Promises more than about 1 kg (2 lb) a week, week after week, or "lose 10 kg in a month" | Aims for about 0.5-1 kg (1-2 lb) a week once the early water weight has gone |
| You must buy their supplements, pills, teas or "fat burners" | Built around normal food from the supermarket; any branded meals are optional |
| Very low calorie (roughly 800 kcal a day or less) with no doctor checking on you | Very low-calorie phases only happen under medical supervision |
| Stops when the weight is off, with no plan for what comes next | Has a maintenance phase with support for months afterwards |
| Hard to find the price, the cancellation terms or how auto-renewal works | Clear total price and a cancel button you can find in under a minute |
| "Clinically proven" with no study named or linked | Names its research, or points to guidelines from bodies like the NIH or NHS |
| Guaranteed or "effortless" results, or one hidden cause behind everyone's weight | Honest that results vary and that it takes steady effort |
| Discourages you from talking to your doctor | Asks about your health and medication, and tells you when to see your doctor |
Why 1-2 lb? It's the pace US and UK health bodies recommend. Your first week may show a bigger drop, especially on a low-carb plan, because of water. The warning sign is a promise that fast loss will keep going.
What a good program includes
Credible programs, from a free app to a clinic, tend to share the same building blocks:
- A realistic eating plan. It creates a modest calorie deficit using foods you'd actually buy, like chicken, lentils, oats, frozen vegetables and fruit, and it still gives you enough protein, fibre and nutrients.
- Help changing habits. Things like planning meals, handling cravings, eating out and getting back on track after a bad weekend. Willpower alone isn't a plan.
- Movement that suits you. A 20-minute walk counts. Be wary of one punishing routine for everybody.
- Regular check-ins. Weekly weigh-ins, a coach, a group or app feedback. Someone or something should notice when you stall.
- A maintenance phase. What you'll eat when you stop losing, and support for at least several months after.
Questions to ask before you pay
Ask by email or chat so you have the answers in writing.
- What is the total cost for 12 months, including food, shakes, supplements and any sign-up fee?
- Does it auto-renew? How do I cancel, and is there a refund window?
- Who designed the program, and what are their qualifications? Is there a registered dietitian or doctor involved?
- What does a typical member lose in 6 and 12 months? Not the best result, the typical one.
- How many people finish the program?
- Do I have to buy any products to follow it?
- What happens when I reach my goal, or if I stop losing weight?
- Who should not do this program? (If the answer is "no one", that's a red flag.)
When you need a doctor involved
Talk to your doctor before starting if you take medicine for diabetes or blood pressure, since losing weight or eating fewer carbs can push both too low. The same goes if you're pregnant or breastfeeding, have kidney or heart disease, have had an eating disorder, or have lost weight without trying.
Any very low-calorie plan, roughly 800 kcal a day or less, needs medical supervision, as does anything involving prescription medication. If you're unsure, read are online diet plans safe?
GLP-1 medication programs
Many online programs now offer weight-loss injections such as semaglutide (sold as Wegovy) or tirzepatide (sold as Zepbound). These can help some people lose a meaningful amount of weight. But they are prescription medicines, and they come with their own checks.
- You need a real clinician. A legitimate service reviews your medical history, checks whether you qualify and follows up on side effects. In the US, these drugs are generally approved for adults with a BMI of 30 or more, or 27 or more with a weight-related condition like high blood pressure or type 2 diabetes. Rules differ in other countries.
- Be careful with compounded and cheap online versions. The FDA has warned about unapproved, counterfeit and compounded versions sold online, including products labelled "for research use only". If a site sells the drug without a proper consultation, don't buy it.
- Expect side effects. Nausea, diarrhoea and constipation are common, especially when the dose goes up.
- Ask about the long term. Studies suggest many people regain weight after stopping. Ask the program what the plan is for food, activity and coming off the medicine.
Also check the price after any intro offer, and whether the membership fee is separate from the medicine.
What it really costs
The price on the homepage is rarely the whole story. Before you sign up, add up a full year:
- The membership or subscription, at the price after any trial or first-month discount.
- Required products such as shakes, bars, pre-packed meals or supplements.
- Your normal groceries, which you still buy on top of any branded food.
- Coaching, check-ins or consultations that cost extra.
- For medication programs, the drug itself, which can cost hundreds of dollars a month without insurance.
Spending more doesn't guarantee a better result. Pay when it buys something you know you need, like a coach or medical supervision.
Types of program compared
| Type | Good for | The catch |
|---|---|---|
| Self-directed (free or cheap apps, guides like the Mediterranean diet) | People who are fairly healthy and like working things out on their own | No one notices if you drift. Many apps upsell hard once you're in. |
| Commercial programs (coaching, points systems, meal plans, meal delivery) | People who do better with structure, weigh-ins and a group | Costs add up fast with required food, and results often fade once you stop. |
| Medically supervised (clinics, GLP-1 medication services, very low-calorie plans) | People with health conditions, on medication, or with a lot of weight to lose | The most expensive option. Check that the care is personal, not a quick questionnaire. |
Still deciding what kind of eating plan suits you? Start with how to choose a diet, or browse more in weight loss.
Common questions
How much weight is safe to lose per week?
About 0.5-1 kg (1-2 lb) a week is the usual guidance once the first week or two are over. You may lose more at the start because of water, but a program promising fast loss week after week is a red flag.
How can I tell if a weight-loss program is a scam?
Look for guaranteed or very fast results, required supplements, "clinically proven" claims with no study named, hidden prices or tricky auto-renewal, and pressure to sign up today. Two or more of those and you should walk away.
Are free apps as good as paid programs?
They can be. A free app works well if you're healthy and motivated on your own. Paid programs are worth it when they add something you'll actually use, like a coach, a group or medical supervision. Fit matters more than price.
Are online GLP-1 weight-loss programs safe?
They can be if a licensed clinician reviews your health, prescribes an approved medicine and follows up with you. Avoid sites that sell the drug without a proper consultation, and be cautious with compounded or "research use" versions, which the FDA has warned about.
What if a program tells me not to talk to my doctor?
Treat that as a serious warning sign and don't sign up. A trustworthy program encourages you to involve your doctor, especially if you take medication or have a health condition.
Weight loss can change how your diabetes and blood-pressure medicines work, and prescription weight-loss drugs have real side effects. If you have a health condition, take regular medication, are pregnant or have had an eating disorder, talk to your doctor before starting any program. See the medical disclaimer.