Does obesity cause snoring?
The question of whether obesity causes snoring is a complex one. Having neck fat has been found to directly cause snoring. This is because the excess fat gathered around the neck can constrict the airways and cause difficulty in breathing. In some cases, it can even lead to snoring or other sleep problems. However, weight loss has not been shown to directly help with snoring.
This was shown by a cross-sectional study that evaluated the link between obesity and snoring This study involved 196 males and 153 females. Their spouses were asked about snoring. They were divided into low normal, high normal, pre-obesity, and obese BMI groups based on their height, weight, neck circumference, and BMI. The study found that weight reduction is not helpful in all adult snorers. 
Why would a skinny person snore?
Snoring isn’t just exclusive to people who are overweight; even those with healthy body weights can suffer from this condition. It is actually more common than most people think, and in some cases, can be easily dismissed as innocuous. Skinny people often snore due to existing anatomical factors such as enlarged adenoids, allergies, and having a narrow airway. This can block the passage of air while someone is asleep which can cause vibrations in the throat thus resulting in snoring noise. Additionally, poor sleeping posture could also lend itself to increased snoring due to obstruction of a person’s airway which may happen when they use an uncomfortable pillow or sleep on their back.
Sleep apnea and obesity – are they related?
Obesity has been linked to Obstructive Sleep Apnea (OSA) syndrome, which causes an individual to periodically stop breathing during sleep. In fact obese or severely obese patients are nearly twice as likely as normal-weighted adults to have OSA.  One explanation for this finding could be that obesity worsens OSA due to fat deposition at specific sites.
The link between sleep apnea, obesity, and high blood pressure
It is possible that obesity may worsen OSA because of fat deposition at specific sites.
Increasing evidence links OSA to illnesses such as high blood pressure (hypertension), stroke, heart attack, diabetes, gastric reflux disease, nocturnal angina, heart failure, hypothyroidism (thyroid hormone deficiency), and an irregular heart rhythm. About half of OSA patients have hypertension (high blood pressure), and untreated OSA raises the risk of heat-related illness and mortality.
Since we know that obesity and diabetes are risk factors for cardiovascular disease, it’s important from a health perspective for people to maintain a healthy body mass index (BMI) as well as healthy blood sugar levels.
Is obesity linked to sleep quality and quantity?
A recent study found that obese people with shorter sleep duration have twice as many subjective sleep problems as non-obese people.  This is an important finding, given that on average obese people are more likely to get less sleep than those of a healthy weight.  Poor quality and quantity of sleep can worsen various metabolic functions such as glucose control, reducing the energy balance in your body, which can cause further weight gain. Weight loss is therefore essential if you are overweight or obese and experiencing poor sleep.
1. Does ‘weight reduction’ help all adult snorers https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3644827/
2. Interactions Between Obesity and OSAS https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3021364/
3. Short sleep duration and obesity: the role of emotional stress and sleep disturbances https://pubmed.ncbi.nlm.nih.gov/18253159/
4. OSAS and Obesity: Implications for Public Health https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5836788/