The short answer is yes, apples are generally a good diet food. They're low in calories, they can often provide a sweet crunchy alternative to much more unhealthy snacks. They're a low glycaemic index food, which means they don't cause a sugar spike leaving you hungry later. They're also a good baking ingredient which can substitute out for higher calorie foods in terms of volume. 

There have actually been a few studies on apple consumption and weight loss specifically, and they did in fact show positive results. This is generally true across most high volume low calorie foods. If you fill up on things that don't contain many calories, then you tend to consume less calories in general, which is hardly shocking. 

There are also some studies that suggest compounds contained in apples can help you lose weight, but the volume of these required is beyond what you're going to get in your average granny smith, and the results are still mixed.

So yes, eating apples instead of other less healthy foods is good for weight loss, but they're not a magic solution. 

The Studies on Apples and Weight Loss

A few studies conducted on humans have also shed light on the potential weight loss benefits of apples. In the most well known study, overweight individuals consumed either whole apples or apple juice for a duration of 4 to 12 weeks. The results demonstrated a significant reduction in body weight. These findings suggest that incorporating apples into the diet of overweight individuals may lead to weight loss. [1] Another study similarly showed that consuming 3 apples or pears a day helped overweight participants lose more weight than the control group, suggesting that it helped them stick to the diet thus losing weight faster when consuming apples.

It should also be noted that apple juice is significantly lower calorie than most fruit juices.

Low in Calories, High in Fiber

 One of the reasons apples are often recommended for weight loss is their low calorie content. With options ranging from as low as 80 calories in a small Granny Smith to around 125 calories in a larger honey crisp, apples are an excellent choice for those looking to reduce their caloric intake. By swapping higher-calorie snacks with apples, you can naturally lower your net caloric intake and promote weight loss.

In addition to being low in calories, apples are also high in fiber. A medium-sized apple contains around 5 grams of fiber, which makes up a significant portion of the recommended daily intake for both men and women. Fiber is known for its ability to promote feelings of fullness and curb appetite, [3] which can lead to decreased calorie consumption. Moreover, fiber plays a crucial role in maintaining a healthy gut and may impact how our bodies metabolize and use energy.

Hydration and Weight Loss

Staying hydrated is essential for overall health, and it turns out that apples can contribute to your hydration goals. Apples have a high water content, with approximately 86% water. This makes them a refreshing and filling snack option that can help you stay hydrated throughout the day. Research has shown that increased hydration can significantly contribute to weight loss and fat loss. By incorporating water-rich foods like apples into your diet, you can support your weight loss efforts while enjoying a delicious and hydrating snack. [4]

The Glycemic Index and Blood Sugar Control

When it comes to weight management, stabilizing blood sugar levels can play a crucial role. Apples have a low glycemic index (GI), which means they cause a slower and more controlled rise in blood glucose levels compared to high-GI foods. By consuming foods with a lower glycemic index, you can help keep your blood sugar levels steady and prevent sudden spikes and crashes that can lead to increased hunger and overeating. Apples, with their low GI, can be a valuable addition to a weight loss diet, contributing to better blood sugar control and appetite management. [5]

Antioxidants and Inflammation

Apples are rich in antioxidants, particularly quercetin, which has been shown to have anti-inflammatory properties. Inflammation in the body is associated with obesity and insulin resistance, which can hinder weight loss efforts. Quercetin, by reducing inflammation, may help improve insulin sensitivity and support weight management. Including apples in your diet can provide you with these beneficial antioxidants, potentially aiding in your weight loss journey. Although the volume of Quercetin in apples is not enough for weight loss by itself, so you'd have to eat other quercetin rich foods for this benefit.

Convenience and Sustainability

When it comes to maintaining a healthy diet, convenience is key. Apples offer a convenient and portable snack option that can be easily incorporated into your daily routine. By making healthy options like apples visible and easily accessible, you are more likely to choose them as a snack, leading to long-term sustainability in your weight loss efforts. Placing a fruit bowl on your countertop can serve as a visual reminder to grab an apple instead of reaching for less healthy alternatives.

Conclusion: Are Apples Good For Weight Loss?

In conclusion, apples can be a valuable addition to your weight loss journey. With their low calorie content, high fiber content, hydrating properties, low glycemic index, and rich antioxidant profile, apples offer numerous benefits that support weight loss efforts. Incorporating apples into your diet as a snack or as part of balanced meals can contribute to feelings of fullness, improved blood sugar control, and better overall health. So, next time you're looking for a healthy and satisfying snack, reach for an apple and enjoy its weight loss benefits.

What Are The Best Apples For Weight Loss?

Regardless of the variety, apples are low in calories, high in fiber, and packed with essential vitamins and minerals. But, some apples are a little bit better in terms of calorie to volume than others.

Granny Smith Apples: The Tart and Crispy Contender

Granny Smith apples are renowned for their tart flavor and vibrant green skin. These apples have a crisp texture, making them a popular choice among weight-conscious individuals. With approximately 95 calories and 4 grams of fiber per medium-sized apple, Granny Smith apples are an excellent option for those looking to reduce their calorie intake while increasing their fiber consumption. The high fiber content promotes satiety, helping with portion control and preventing overeating. Moreover, the tartness of Granny Smith apples adds a refreshing twist to your snacking experience.

Pink Lady Apples: A Splash of Color and Flavor

Pink Lady apples are known for their vibrant pink or blush-colored skin and their sweet-tart flavor. These apples are slightly larger in size and contain around 95 calories and 3 grams of fiber per medium-sized apple. While Pink Lady apples have a slightly higher calorie content compared to Granny Smith and Gala apples, they still offer a decent amount of fiber, making them a satisfying and nutritious choice for weight loss. The vibrant color and unique flavor profile of Pink Lady apples add a delightful touch to your snack time.

Gala Apples: Sweetness with a Healthful Twist

Gala apples offer a delightful combination of sweetness and health benefits. These apples have a crisp and juicy texture, making them a favorite among apple enthusiasts. With around 80 calories and 4 grams of fiber per medium-sized apple, Gala apples provide a slightly lower calorie option compared to Granny Smith apples. However, they still offer a significant amount of fiber, contributing to feelings of fullness and supporting weight management efforts. The natural sweetness of Gala apples makes them a satisfying and nutritious choice for weight loss.

Red Delicious: The Antioxidant-Rich Apple

The Red Delicious apple is a classic favorite known for its vibrant red color and sweet flavor. This variety of apple is rich in anthocyanidins, which are pigments responsible for the red, blue, and purple hues in fruits and vegetables. Anthocyanidins are potent antioxidants that belong to the polyphenol group. Red Delicious apples also contain high levels of other polyphenols, such as epicatechin, flavonoids, flavonols, and phloridzin. These antioxidants contribute to the overall health benefits of Red Delicious apples. Interestingly, the antioxidant content is higher in the peel than in the pulp of all apple varieties. Red Delicious apples are also a good source of calcium, with the highest calcium content among the apple cultivars analyzed in a studies.

Fuji: The Choice For A Sweet Tooth

Fuji apples are renowned for their sweet flavor, yellow and red peel, and crisp texture, which contribute to their widespread popularity. When it comes to polyphenol content, Fuji apples consistently rank high compared to other apple varieties. Additionally, test-tube studies have been conducted specifically on Fuji apples extract may improve glucose metabolism and potentially benefit individuals with insulin resistance, a primary symptom of type 2 diabetes, [6] but obviously these studies are far from conclusive and a lot of other apples have the same content. But, the main reason we like these for weight loss is the fact that they're particularly sweet helping scratch that sweet craving itch.

References 

1 - https://pubmed.ncbi.nlm.nih.gov/12620529/

2 - https://pubmed.ncbi.nlm.nih.gov/29630462/

3 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6768815/

4 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4901052/

5 - https://pubmed.ncbi.nlm.nih.gov/34352885/

6 - https://pubmed.ncbi.nlm.nih.gov/35205973/