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Is excess, unwanted weight frustrating you? Have you surfed the Internet just like millions of others looking for the latest weight loss remedies?
If your answer to both these questions is yes, then you must have come across the General Motors (GM) diet and heard about its claims for success. But before you commit yourself to this particular diet, it’s good to analyze it and sift fact from fiction.
Background Story of GM Diet
The GM diet has its origin dating back to 1985 when it was developed by the automobile giant, General Motors (GM) for its employees.
The story goes on that the diet was designed to help GM employees deal with weight gain resulting from the sedentary work environment, and achieve weight loss. It is also said to focus on improving a person’s health, mental performance, and overall activity.
It’s rumored that GM received help in formulating this diet from both the United States Food and Drug Administration and the U.S. Department of Agriculture. This has prompted millions to attempt the GM diet, hopeful that it will deliver its promise of swift and effective weight loss.
However, the above story has proven to be nothing but an urban myth. In fact, evidence suggests that the GM company has nothing to do with this diet, and the real origin of this diet is still an enigma.
Let’s take a look at what the diet is all about – its claims, advantages, disadvantages, and the scientific validity of the information available to us.
The GM diet is a 7–day diet plan with a restriction of different food groups on different days during the diet period.
Benefits claimed by the GM diet
The proponents of this diet say that you can attain your desired weight goal in the long term by repeating this diet regularly after a gap of 5 to 7 days.
However, Carol Aguirre (MS, RD/LDN) says, “One of the most popular benefits of the GM diet is quick weight loss; however, don’t expect that weight loss to be long term. It helps with bowel movements due to all the fiber intake from fruit and veggies.”
This diet is not recommended for diabetics, (1)(2) nursing mothers, and those with hormone or heart-related disorders, as eating select foods can wreak havoc on the blood sugar levels and cause an imbalance of nutrition.
Claims on How the GM Diet Works
According to Aguirre, “The GM diet may work to jump start your weight loss, but don’t expect lasting results. The diet is low in fat, sugar, and sodium which will help with weight loss. However, the weight you’re losing is most likely water weight, not fat.”
- Many of the foods included in the diet are low in calories but also very satiating – such as fruit and vegetables. (3) This promotes weight loss by creating a calorie deficit; you burn more calories than you consume. (4)
- Many of the foods in this diet are described as “negative-calorie foods,” which means they supposedly provide fewer calories than they take to digest.
- Many of the foods (i.e., produce) in the diet are also high in water content and dietary fiber, making them low in energy. They displace more calorie – and fat-rich foods, which are energy-dense, and thereby decrease the total energy consumed. This boosts fat loss from the body. (5)
- Each day of the GM diet permits you to eat different foods or food groups.
- As it is a 7-day eating plan, you do not have to commit to the strict diet plan long term.
Dietary Rules for the GM Diet
The GM diet is spread over 7 days, with specific instructions for each day. Each day of the GM diet permits you to eat different foods and from different food groups.
You are advised to drink 8 to 12 glasses of water each day to stay hydrated while being on the GM diet. (6)
- Exercise is optional while on this diet. You are strictly instructed not to exercise for the first three days of the diet, as the body may feel weak and stressed due to the low-calorie intake.
- Beans are not permitted as part of the diet, as it claims the high calories in most legumes do not help in promoting weight loss.
- Coffee and green tea without sugar are permitted.
- Milk can also be substituted with soy milk or almond milk.
- Processed or packaged food items may not be consumed.
- Alcohol and sodas are a strict no-no during the week. (7)(8) Diet sodas are also strictly forbidden.
- Fruit juices may only be consumed on Day 7.
Specific guidelines followed for each day of the GM diet
Day 1: Eat fresh fruits
The aim of Day 1 of the GM diet is to “cleanse” the body’s digestive system and boost metabolism on an all-fruit diet.
- Adherents need to eat fruits with high water content except for bananas. The fiber in the fruits is said to help clean your system. A higher fruit intake is also associated with weight loss. (3)
- According to the diet, eating melons, especially watermelons – is recommended to help lose up to 3 pounds (1.3 kg) on the very first day. Cucumbers can also substitute melons.
- Citrus fruits like oranges and grapefruit are also highly recommended on the first day. However, you are advised not to eat them on an empty stomach.
- There is no restriction on the number of fruits you can eat on Day 1.
Day 2: Eat vegetables
The aim of Day 2 of the GM diet is to increase fiber intake. The diet claims that this is to help your body regulate the sugar content from the all-fruit diet consumed on Day 1. A high fiber intake has been shown to increase the feeling of fullness and promote weight loss. (9)
You are advised to eat only vegetables, either cooked or raw. Green vegetables such as kale, lettuce, and spinach are suggested.
- The diet promotes eating vegetables as a way to help cleanse your stomach, intestines, and liver and induce your body into a calorie-burning mode for weight loss.
- If eating vegetables raw, such as in the form of a salad, do so without a high-calorie salad dressing. A light dressing of white wine vinegar, lemon juice, and raw herbs for flavoring may be used. If cooked, vegetables should be prepared using a small amount of healthy oil, like olive oil. (10)
- There is no limit on the number of vegetables you can consume.
- All non-vegetables, such as fruits, eggs, dairy, nuts, beans, and mushrooms, are prohibited on Day 2 of the GM diet.
Day 3: Eat fresh fruits and vegetables
Both fruits and vegetables can be eaten on Day 3 of the GM diet.
- A variety of fruits and vegetables are believed to provide a good amount of vitamins, minerals, and other nutrients to keep your body strong and healthy. (11)
- There is really no limit on the amount of vegetables and fruits you can consume.
Day 4: Bananas, milk, and special GM soup
Day 4 of the GM diet narrows your food choices to three items: bananas, milk, and a special vegetable soup that is also known as the GM “Wonder Soup.” This soup includes cabbage, celery, green peppers, onions, tomatoes, lemon, carrots, and red chilies.
- The addition of milk and bananas is said to give your body protein and energy to keep you full and energized throughout the day. (12)
- It is also claimed to help replenish the sodium and potassium that were unavailable during the first three days of the diet.
- Followers of the diet are suggested to consume 3 cups of skim milk, 5 to 6 medium-sized bananas and 2 bowls of the special GM soup on Day 4.
Day 5: Lean meat and tomatoes
You will find Day 5 of the GM diet to be more satisfying for your taste buds.
- You are allowed to have protein in the form of lean meats, including red meat, chicken, and fish. You can have up to 1 pound of meat over the course of the day.
- This good amount of protein, iron, fiber, and lycopene from the lean meats and tomatoes is suggested to help your body recover from any muscle weakness you may have due to the strict diet you’ve been following for the last four days. (13)
- You are also allowed to eat up to six tomatoes on Day 5, which can be eaten along with your meat or made into tomato soup.
- Water intake should be increased by two glasses. This helps to flush out the excess uric acid that may have accumulated due to the consumption of meat. (14)
- Vegetarians may have cottage cheese, tofu, or brown rice instead of meat.
Day 6: Brown rice, lean meat, and cooked vegetables
On Day 6 of the GM diet, you can feast on brown rice, vegetables, lentils, mushrooms, and any lean meat of your choice.
The protein from the meat and the fiber from the vegetables are said to keep your appetite under control during the day. (15)
Day 7: Brown rice, vegetables, and fruit juices
On Day 7, the last day of the GM diet, you are supposed to eat brown rice with cooked vegetables and fresh fruit juices.
All fruits, including bananas, mangoes, and pears – as well as potatoes, sweet potatoes, beans, lentils, and mushrooms are to be avoided on Day 7. All dairy and meat products are also a strict no-no on the last day of the diet.
Professed changes after finishing the 7-Day GM diet:
- You will be slimmer by several pounds.
- You will be able to enjoy better sleep (more tired at night and more refreshed when you wake up).
- Your digestive system will work better.
- You will have glowing skin.
- You will become much more active than before.
A sample 7 day GM diet plan:
- For breakfast (8 a.m. to 9 a.m.) – Start with an apple and a small bowl of watermelon. Don’t forget to drink 2 glasses of water after your breakfast.
- For a mid-morning snack (10:30 a.m. to 11 a.m.) – Enjoy a bowl of raw papaya. Again, drink 2 glasses of water.
- For lunch (12 p.m to 1:30 p.m.) – Eat a bowl full of fruits like watermelon or muskmelon. Drink 2 glasses of water again.
- For an afternoon snack (4 p.m. to 4:30 p.m.) – Eat an orange or sweet lime and drink 2 glasses of water.
- For an evening snack (6 p.m. to 6:30 p.m.) – Drink a glass of highly nutritious coconut water.
- For dinner (8 p.m. to 9 p.m.) – Eat a bowl of melon and drink 2 glasses of water.
- For breakfast (8 a.m. to 9 a.m.) – Start Day 2 by eating 1 cup of baked or boiled potatoes with a little bit of butter. This will give you enough energy for the rest of the day. Do not forget to drink 2 glasses of water.
- For a mid-morning snack (10:30 a.m. to 11 a.m.) – Eat a bowl of raw cabbage (preferably red cabbage) or raw lettuce. You can tear the leaves to shreds and sprinkle a bit of salt and black pepper on them to taste. Drink 1 to 2 glasses of water.
- For lunch (12 p.m. to 1 p.m.) – You can have 1 cucumber, 1 tomato and ½ beetroot (boiled). Drink 2 glasses of water.
- For an evening snack (5 p.m. to 6 p.m.) – Eat 1 cup of cherry tomatoes or 2 regular tomatoes raw with a little bit of seasoning. Also, drink 2 glasses of water.
- For dinner (7 p.m. to 8 p.m.) – You can eat a medium-sized bowl of boiled vegetables like cauliflower, asparagus, broccoli, zucchini, and bell peppers. Just sprinkle some salt and black pepper on them to taste. Drink 2 glasses of water. You may also have 1 cup of spinach soup for dinner. Make it by blanching some spinach leaves in boiling water with a pinch of salt, puree them and garnish the soup with fresh mint leaves. You can consume this extremely healthy soup either hot or cold.
- For breakfast (8 a.m. to 9 a.m.) – Start Day 3 by having an apple or another bowl of superfruit, and watermelon for breakfast. Drink at least 2 glasses of water.
- For a mid-morning snack (10 a.m. to 11 a.m.) – Eat 1 bowl of cantaloupe mixed with papaya, and drink 2 glasses of water.
- For lunch (12 p.m. to 1 p.m.) – Eat a big bowl of raw salad containing Romaine lettuce, cucumbers, pepper and tomatoes along with ½ boiled beetroot. You can add vinegar to your salad. Drink 2 glasses of water.
- For an evening snack (4 p.m. to 5 p.m.) – Eat a mango or an orange. Drink 2 glasses of water.
- For dinner (7 p.m. to 8 p.m.) – You can have a bowl of boiled broccoli, along with some fresh green vegetables like kale, cabbage or lettuce, and a bowl of raw papaya. Again, do not forget to drink 2 glasses of water.
- For breakfast (8 a.m. to 9 a.m.) – Start your day with 1 banana and 1 glass of warm skim milk. You can have sweet almond milk or low-fat coconut milk as well. Also, drink at least 2 glasses of water.
- For a mid-morning snack (10 a.m. to 11 a.m.) – Eat 2 medium-sized bananas and drink 1 glass of milk. Again, drink at least 2 glasses of water.
- For lunch (1 p.m. to 2 p.m.) – Eat 1 bowl of the special GM soup.
- For an evening snack (4 p.m. to 5 p.m.) – Enjoy a banana milkshake (1 glass).
- For dinner (7 p.m. to 8 p.m.) – Eat 1 bowl of the special GM soup along with 1 banana. Again, you should drink about 2 glasses of water.
- For breakfast (8 a.m. to 9 a.m.) – Start with 1 small serving of lean meat (about a quarter-pound) and soup. You may eat the braised meat with 1 medium-sized tomato, sliced and sprinkled with a bit of salt and pepper. Drink 3 glasses of water.
- For lunch (1 p.m. to 2 p.m.) – Enjoy about ½ a pound of grilled meat and pair it with a sliced tomato for added nutrition. Drink 3 glasses of water.
- For dinner (7 p.m. to 8 p.m.) – Consume a small serving of meat (a ¼ pound), 1 bowl of GM soup, and 1 sliced tomato. Drink 2 glasses of water.
Note: On Day 5, do not eat any snacks or have fruit juices. In between your meals, you can drink 2 glasses of water.
- For breakfast (8 a.m. to 9 a.m.) – Start the day with a bowl of stir-fried mixed vegetables with a small serving of lentils. Non-vegetarians can have a bowl of vegetable soup along with beef cutlets. Drink 2 glasses of water.
- For a mid-morning snack (10:30 a.m. to 11 a.m.) – Eat a bowl of salad with raw greens like lettuce or cabbage. The salad can even be topped with cooked lean beef and chicken strips. Drink water again.
- For lunch (12 p.m. to 1:30 p.m.) – You can have ½ a pound of any lean meat, and a small serving of brown rice along with some stir-fried greens like broccoli and spinach. Today, you can even indulge in some mushrooms. Drink 1 to 2 glasses of water.
- For an evening snack (4 p.m. to 4:30 p.m.) – Munch on some sautéed green beans, asparagus or collard/mustard greens. You can top it with cooked lean beef and chicken strips. Drink some water.
- For dinner (8 p.m. to 9:30 p.m.) – Enjoy a bowl of the GM soup or any vegetable soup with ½ a pound of grilled lean meat. Do not forget to drink 2 glasses of water.
- For breakfast (8:30 a.m. to 9 a.m.) – Start with a bowl of brown rice with some vegetables. Do not forget to drink 2 glasses of water.
- For a mid-morning snack (10:30 a.m. to 11 a.m.) – Drink 1 glass of watermelon juice or any other fruit juice of your choice. Drink 2 glasses of water.
- For lunch (12:30 p.m. to 1 p.m.) – Eat another bowl of healthy brown rice and cooked vegetables. You can even have a slice of mango. Also, drink water.
- For an evening snack (5 p.m. to 6 p.m.) – Drink another glass of fruit juice and 2 glasses of water.
- For dinner (8 p.m. to 9:30 p.m.) – Finish off your diet with a bowl of brown rice and stir-fried greens of your choice. Drink 2 glasses of water.
Benefits of the GM Diet
The benefits of the GM diet have not scientifically been evaluated. However, based upon the dietary constituents, nutritionists can assess the pros and cons of such a diet to have a better perspective and its impact on people.
The GM diet is a fusion of complex carbohydrates with high fiber content. (9) It is at the same time low in fats, sugar, and sodium, which aids in weight loss and improves the health overall. (17)(18)
The diet encourages its followers to increase their intake of fruits and vegetables. There are several studies that support the fact that an increased intake of fruits and vegetables promotes a decrease in body weight over time and also a decrease in the waistline. (19) This may be due to the calorie deficit-burning more calories than you consume-as non-starchy vegetables and fruits are generally low in calories and rich in dietary fiber.
The diet also curbs the cravings for sugary foods and alcohol, which are known to increase weight gain in individuals. Sugar-rich diets have been identified as a risk factor for obesity. (20) Alcohol consumption contributes to excess energy intake which is linked to weight gain. (8)
The diet also allows you to make personal choices regarding the kind of fruits, vegetables, and meats you would like to consume, as well as the manner in which they are prepared. This means there is less chance of non-observance of the diet.
Disadvantages of the GM Diet
Like any crash diet, the GM diet has its pitfalls. Some of the drawbacks of the GM diet are the following:
1. Lack of scientific backing
To date, there are no studies that assess the impact of the GM diet on the overall health of individuals. So, there is no concrete evidence endorsing its claims.
There is no evidence to prove that the dietary constituents from the negative calorie foods actually promote the burning of more calories than they provide. Some of the dietary foods constituting the GM diet supply more calories than others. (21)
2. Deficient in vital nutrients
The GM diet is not a balanced diet as it excludes some food groups on certain days. Hence it may tend to be deficient in important nutrients. This may make the person lethargic, dizzy, and weak as the body has to undergo a sudden change from its normal routine.
Also, the GM diet tends to be protein deficient, as rich sources of protein such as eggs and meat are avoided for many days. Adequate protein intake has been shown to help promote satiety and a healthy body weight, so avoiding protein foods entirely may hinder weight loss progress. (22)
The diet is also low in fat and other essential nutrients, like iron, B12, and calcium, to name a few, especially during the first three days. All food groups are essential, and their absence for even a short time can adversely affect the body. (23)
3. Temporary weight loss
The weight shed while on the GM diet is mainly thought to be water weight and not the loss of fat. Glycogen, a carbohydrate-rich in water that is stored in the liver, is the major fuel source of the body when calorie supply to the body is limited and fats are burned upon physical activity.
Hence, water weight loss is temporary, and you may incur weight regain upon switching back to your old eating habits. (24)
The GM diet is a counterintuitive diet because it is not based on our natural lifestyle. As a result, it cannot be continued long term and should not be followed for more than 1 week. It leaves the follower confused concerning what to eat on a regular basis after the diet period is over.
Thus, one is likely to resume eating unhealthy foods, which may lead to weight gain.
Other Possible Side Effects Include
- Headaches and extreme cravings during the first two days.
- You’ll need strong will power to control yourself, and advance preparation may come in handy.
- Hunger pangs at night, which you will need to overcome for the diet to be successful.
- Possible hair loss after completing the diet, due to loss of protein. (25)
- Feelings of fatigue, exhaustion, and tiredness.
- Loss of muscle mass. (26)
GM Diet Tips
- The GM diet may be tried by young adults for a very short period of one week.
- One way to prepare your body for the GM diet is to start having healthier meals with loads of fresh fruits, vegetables, and whole grains at least 3 to 4 weeks before following the GM plan.
- Find a diet buddy to share and support your journey through the diet week. (27)
- Check for underlying health issues that may hinder weight loss, like thyroid problems, hormonal imbalance, and high cortisol levels. Seek treatment, if necessary, from a qualified health specialist.
- Go to bed early by 10.30 p.m. and sleep well for around 8 hours, as adequate sleep can also aid in weight loss. (28)
- Eat your dinner at least 2½ hours before bedtime.
- Avoid frequent snacking before meals.
- Consider other long term dietary changes you can implement in order to try to maintain a healthy lifestyle after the 7 days are over.
From the above evidence presented, we can conclude that the GM diet can lead to weight loss, but this is unsustainable in the long run. It is also detrimental to your health if done frequently, and the diet is not backed by scientific studies.
“The GM diet is not maintainable. You need essential macro and micro nutrients daily; all food groups are essential and eliminating them even for short periods could affect your health. The GM diet is not based on a healthy lifestyle and should not be followed for a long period of time.
The moment you go back to your old eating habits, the weight lost will come back. It is better to switch to a healthy sustainable eating plan that you can follow for a lifetime,” says the dietitian, Aguirre.
A balanced diet remains one of the best and most advocated methods for weight loss, planned with the help of a qualified professional. (29) A healthy, balanced diet should be coupled with regular physical activity so that you can stay fit.
Adhering to a healthy lifestyle, in the long run, will bring fruitful results and a healthy you! Eliminating a food group even for a short time is not the answer.