Weight Loss Fact or Fiction?

Multiple diets feature yogurt as a key component, insisting that this food helps you lose weight quickly.

This section reviews two of these diets to determine whether they’re based on sound science.

The Yoplait Light Two Week Tune Up

One such diet, promoted by actress Jeannie Mai, was known as the Yoplait Yogurt Diet or Yoplait Light Two Week Tune Up. While Yoplait is no longer running the Two Week Tune Up, this popular yogurt diet claimed to help individuals lose 2–5 pounds (1–2.5 kg) over 14 days.

This diet had you eating yogurt at least twice a day. Its rules included specific instructions for meals and snacks:

• Breakfast and lunch: 1 container of Yoplait Lite Yogurt, 1 cup (about 90 grams) of whole grains, and 1 serving of fruit
• Dinner: 6 ounces (about 170 grams) of lean protein, 2 cups (about 350 grams) of vegetables, and a small amount of fat, such as salad dressing or butter
• Snacks: 1 cup (about 175 grams) of raw or 1/2 cup (about 78 grams) of cooked vegetables, as well as 3 servings of fat-free dairy throughout the day

The diet reduced your calorie intake to just 1,200 calories per day and recommended that you increase your physical activity by walking 30–40 minutes every day. Together, these factors result in a calorie deficit, which may help you lose weight (3, 4).

Some proponents of the diet maintained that the focus on fat-free yogurt is also beneficial, claiming that the fat in other yogurts ups your body’s production of the stress hormone cortisol. This increase is thought to boost levels of anxiety and hunger.

While research links higher cortisol levels to an increase in appetite and obesity risk, dietary fat has not been tied to a significant increase in cortisol levels (5, 6, 7).

In fact, fat-free yogurts like Yoplait Light are often higher in sugar, which has been shown to raise cortisol levels and hunger. Additionally, studies associate full fat dairy products with a reduced risk of obesity (8, 9, 10).

One study gave 104 women either the Yoplait Two Week Tune Up or a standard 1,500- or 1,700-calorie diet. After the first 2 weeks, those in the yogurt group had their daily calories increased to 1,500 or 1,700 for 10 weeks (11).

Although women in the Yoplait group lost an average of 11 pounds (5 kg) over the 12-week study period, there was no significant difference in weight loss between the two groups (11).

These results suggest that weight loss from the Yoplait Two Week Tune Up was the result of cutting calories — not eating yogurt.

It’s also worth noting that the study was partially funded by General Mills, which owns Yoplait.

The Yogurt Diet

Nutritionist Ana Luque promotes an eating pattern called the Yogurt Diet in her book of the same name, which says that yogurt is the secret to losing weight and supporting overall health.

Specifically, she declares that the probiotics in yogurt help treat obesity, lactose intolerance, digestive problems, acid reflux, irritable bowel syndrome (IBS), allergies, diabetes, gum disease, yeast infections, slow metabolism, and ulcers.

The book also includes a 5-week detox diet that involves eating several servings of yogurt each day.

While the author asserts that this diet helped her overcome digestive issues and lactose intolerance, there’s currently no evidence to support the effectiveness of her diet plan.

summary

Both Yoplait’s and Ana Luque’s yogurt diets are based on the notion that yogurt promotes weight loss. However, neither diet has been studied for its short- or long-term effectiveness, and the Yoplait diet, in particular, is packed with added sugar.

Several theories suggest that yogurt supports weight loss due to its various nutrients.

The calcium claim

Dairy yogurt is considered an excellent source of calcium, with 1 cup (245 grams) providing approximately 23% of the Daily Value (DV) (12).

Calcium is an essential mineral that’s important for bone health. It has also been studied for its weight loss effects (13, 14).

Test-tube studies reveal that higher blood levels of calcium may reduce fat cell growth. Similarly, animal studies link calcium supplements to significant reductions in body weight and fat mass (14).

However, the effect of calcium on weight loss in humans is mixed.

A study in 4,733 people associated calcium supplements with significantly less weight gain over time in children, adolescents, adult men, premenopausal women, and adults with a healthy body mass index (BMI) (15).

However, the overall effect of the supplements was quite small. On average, those taking calcium gained 2.2 pounds (1 kg) less than those not taking the supplements (15).

A few other studies suggest that dietary or supplementary calcium may aid weight and fat loss in children, post-menopausal women with obesity, and men with type 2 diabetes (16, 17, 18).

Yet, several other studies don’t show a significant link between increased calcium intake and weight loss (14, 19, 20, 21, 22).

As such, more research on yogurt’s calcium content is needed.

The protein claim

Yogurt’s protein content may aid weight loss in various ways. These include:

• Regulating hunger hormones. A high protein intake has been found to increase levels of several appetite-reducing hormones. It also reduces levels of the hunger hormone ghrelin (23, 24, 25).
• Upping your metabolism. A high protein diet may boost your metabolism, helping you burn more calories throughout the day (26, 27).
• Keeping you feeling full. Increasing your protein intake has been shown to increase feelings of fullness and satisfaction. Thus, a high protein diet may naturally encourage you to consume fewer calories throughout the day (28, 29).
• Helping preserve muscle during weight loss. Alongside a reduced calorie intake, a high protein diet may help preserve muscle mass while promoting fat loss, especially when combined with resistance exercise (30, 31, 32).

One cup (245 grams) of yogurt boasts anywhere from 8 grams of protein in regular yogurt to 22 grams in Greek yogurt (12, 33).

However, this dairy product isn’t unique in its protein content. Foods like lean meat, poultry, fish, eggs, beans, and soy are also excellent sources of protein (34).

The probiotics claim

Yogurt is a good source of probiotics, which are beneficial bacteria that support gut health (35, 36).

While research is limited, early studies suggest that probiotics — especially those containing Lactobacillus bacteria, which is common in yogurt — may help you lose weight and belly fat (37, 38, 39).

A 43-day study in 28 overweight adults found that eating 3.5 ounces (100 grams) of yogurt with Lactobacillus amylovorus per day resulted in greater reductions in body fat than yogurt without probiotics (39).

While these results are promising, further research is needed.

summary

Yogurt is a good source of calcium, protein, and probiotics. While more studies on calcium and probiotics are necessary, its protein content may support weight loss.

Its nutrients aside, you may wonder what studies show about yogurt and weight loss. Notably, various ways of including it in your diet may change how it affects your weight.

Adding yogurt to your diet

In a 2-year study in 8,516 adults, those who ate more than 7 servings of yogurt per week were less likely to have overweight or obesity than individuals who ate 2 or fewer servings per week (40).

Similarly, a study in 3,440 people found that those who ate at least 3 servings of yogurt per week gained less weight and had smaller changes in waist circumference than those who ate less than 1 serving per week (41).

While intriguing, these studies are observational and cannot prove cause and effect.

In a review of six randomized controlled trials — the gold standard of scientific research — only one study determined that yogurt had a significant effect on weight loss (2, 42).

As such, while those who regularly consume yogurt may be less likely to have overweight or obesity, research doesn’t currently show that simply adding it to your diet aids weight loss.

Replacing other foods with yogurt

Interestingly, replacing a high fat, low protein food with yogurt may boost weight loss.

One study gave 20 healthy women either 160 calories (6 ounces or 159 grams) of yogurt as an afternoon snack or the same number of calories from high fat crackers and chocolate (43).

When eating yogurt, the women reported feeling fuller for longer. Furthermore, they consumed an average of 100 fewer calories at dinner (43).

Thus, replacing other snack foods with yogurt may help you control your appetite and consume fewer calories.

summary

While regularly eating yogurt is linked to a reduced risk of excess weight and obesity, it’s unclear whether simply adding it to your diet aids weight loss. That said, replacing low protein, high calorie snacks with yogurt is likely to help.

Although yogurt can be part of a nutritious diet, not all products are healthy.

In fact, many yogurts pack high amounts of added sugar, especially fat-free and low fat flavored varieties.

Diets high in added sugars are associated with an increased risk of obesity and weight gain, as well as conditions like heart disease and type 2 diabetes (44, 45, 46, 47).

Thus, you should read the label on yogurt before buying it. Plain and unsweetened yogurts are best, as they don’t contain added sugars.

Summary

As many yogurts are high in added sugars, it’s important to read labels and opt for plain or unsweetened varieties.

Yogurt can make a nutritious and versatile addition to your diet. Here are some healthy ways to incorporate it into your routine:

• Top it with berries, nuts, and seeds for a balanced breakfast or filling snack.
• Add it to smoothies.
• Stir it into overnight oats.
• Top hot oatmeal, protein pancakes, or whole grain waffles with a dollop of yogurt.
• Mix it with herbs and seasonings to make dips, salad dressings, and spreads.
• Replace sour cream with whole milk yogurt on tacos and burrito bowls.
• Use it in place of butter in baked goods, such as muffins and quick breads.

summary

Yogurt is a versatile ingredient that can be enjoyed on its own as a breakfast or snack. It can also be used in cooking and baking.

As an excellent source of calcium, protein, and probiotics, yogurt has been lauded as a weight loss aid.

Still, fad diets like the Yoplait Two Week Tune Up and Ana Luque’s Yogurt Diet aren’t well studied and may even have negative health effects.

Yogurt may be most beneficial for weight loss when used to replace high calorie, low protein foods rather than when simply added to your diet. As it may help you feel full for longer, this dairy product could naturally lead you to eat fewer calories throughout the day.

Furthermore, regular yogurt intake is tied to a reduced risk of excess weight and obesity.

Overall, eating yogurt as part of a balanced diet can be a nutritious and satisfying way to support weight loss.