Overweight and obesity pose a serious public health challenge around the world. Many dietary plans available online do not comply with dietary recommendations and are nutritionally unbalanced. The aim of this study was to assess women’s knowledge about the safe use of alternative weight loss diets, as well as to evaluate the results of using alternative diets in the studied popula- tion and their impact on health and well-being. The study was conducted between October 2023 and June 2024. The inclusion cri- teria were: female gender, age of 19-65 years, and adherence to alternative diets, including weight loss diets. The research method was a survey questionnaire on, among other things, frequency of consumption of different food groups, eating habits, adherence to alternative weight-loss diets, type of diet, motivation to lose weight, dietary goals, duration of the diet, results, potential side effects, and the participants’ general health and well-being. A total of 393 women participated in the survey. Nearly half of the participants were unfamiliar with the term “alternative diet”, and more than 40% of the surveyed women were unable to give an example of an alternative diet. The respondents were most familiar with the vegetarian diet, the Dukan diet, and the blood type diet. The largest group of participants (38.9%) were not familiar with the health risks and/or health benefits associated with un- conventional diets, whereas more than 25% of the women were of the opinion that alternative diets can provide health benefits. In a group of women following alternative weight loss diets only less than a third of the studied population strictly adhered to a restrictive diet; 33% of the respondents modified their meals, and 1/5 of the women snacked between meals. Long-term use of alternative diets may cause negative side effects, such as deterioration in well-being, digestive problems and mood swings.