( CNN ) -- Anita Mills was 382 pounds when a family doctor gave her four simple rules to lose weight : . 1 . Eat 8 ounces of food every 3 hours . 2 . No sugary drinks . 3 . Do not skip meals . 4 . Do not tell anyone what you 're doing . Now 242 pounds lighter , Mills credits that last tip for helping her through the most difficult months of her weight loss journey . Not having someone questioning every bite or trying to persuade her to relax on weekends helped her focus on the goal . `` It 's so much better to walk into a room and have someone say , 'Hey , did you do something different ? ' than to announce , ' I 'm on a diet , ' and have people pointing fingers at you , '' she said . The advice seems counterintuitive . Weight Watchers and similar groups tout support as a major reason for their programs ' success , and studies have found that accountability is important in accomplishing a goal . But telling family , friends and Facebook about your diet plans could have a detrimental effect , some experts say . Mills ' doctor , Jon Walz , gives all of his weight loss patients the same rules . He blames the need for secrecy on the culture of obesity . Since childhood , he says , we 've searched out people who look and act like us . `` People who are obese live with obese people . They find obese friends . Most ( patients ) do n't recognize how bad a lifestyle they have , how self-defeating a lifestyle is.. They think that culture 's normal . '' As human beings we have a difficult time with change , Walz continues . So when someone we love alters his or her lifestyle , we have a problem dealing with it -- even if that transformation is positive . `` Deliberately or not , the family , the friends , the other people who are part of that individual 's culture will resist the change , '' Walz says . `` ( They ) will try to change them back to what the culture tolerates . '' Mills has discovered the truth in his theory . After she dropped a significant amount of weight , she could n't hide her diet anymore . That 's when friends started drifting away . `` People are mean -- people who you would normally think would be supportive . One friend told me she liked it better when I was the fat friend . That hurt , '' Mills said . There are other reasons to keep your weight loss plans to yourself . Dr. Peter Gollwitzer , a professor of psychology at New York University , studies how goals and plans affect cognition and behavior . In his research paper , `` When Intentions Go Public , '' Gollwitzer describes how spilling the beans -- and the resulting response -- can change someone 's actions . Everyone has what Gollwitzer terms an `` identity goal '' of some kind , whether it 's to be a good mother or a better scientist . In the case of weight loss , that goal is to be a successful dieter . To reach an identity goal , you need indicators of your accomplishments . For a scientist it 's published research papers or a boss ' recognition . For a dieter it could be pounds dropped or praise from friends/family when they see how great you look . Gollwitzer 's studies found that when you tell people what you intend to do , and that intention is acknowledged , the recognition qualifies as an indicator of accomplishment . `` The danger is that you feel that you have already reached the goal and because of that you do n't have to act on it any more , '' Gollwitzer says . In other words , when you tell a friend that you 're planning to drop 20 pounds and she notices your good intention , you no longer feel the need to follow through with exercise or healthy eating . There are a number of ways to avoid this phenomenon . `` One is simple -- you can keep your mouth shut , '' Gollwitzer says . `` Another one is to form different kinds of intentions , not only say what you want to do but also when , where and how you want to do it . '' Such planning helps create situational action control , he explains . When you find yourself at the gym before work , the situation you mentally mapped out controls your behavior instead of your intention to exercise more . The third way , Gollwitzer says , is to tell only one or two people who hold power over you ( metaphorically ) so that they help you stick to your intentions . Select those people carefully , fitness and nutrition expert Bonnie MeChelle warns . The author of `` Accountability is Key '' says people with negative energy or a trainer that does n't fit your style , wo n't help . But if you do find someone who will hold you responsible , share away . `` Tell them everything , '' MeChelle says . `` Accountability is key because if you keep everything to yourself , no one is going to know what you 're doing -- no one is going to know if you fall off the wagon . '' Whether you choose to share your diet plans or keep them secret , it 's important to remember exactly who you 're losing weight for . `` If you 're losing weight to please other people , your motivation will not be sustained to keep going when the going gets rough , '' MeChelle says . And until you drop those extra pounds , you 're the only one who has to know .
Dr. Jon Walz tells all his weight-loss patients to keep their diet plans secret . Research shows telling people your plans can have a detrimental effect . Accountability is key , fitness expert says , but you have to pick your guides carefully .