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About the Author
Dr. Karen Vieira, PhD MSM
Dr. Vieira is a research scientist with a PhD in Biomedical Sciences from the University of Florida College of Medicine Department of Biochemistry & Molecular Biology. She has done clinical and laboratory research on diseases, cellular functioning and nutritional supplements. Her focus is helping people make dietary and lifestyle changes that prevent, cure or improve health conditions.
According to the American Psychiatric Association, substance abuse is the excessive use of substances, including alcohol and drugs, that cause an individual to suffer from clinical impairments as well as the dramatic loss of academic, professional, and social skills .
Substance abuse also dramatically alters the diet and in most cases, it leads to irregular eating patterns and poor nutrition. As a result, previously healthy adolescents and adults may begin to experience significant health problems shortly after the substance abuse begins.
This guide will describe the negative effects that substance abuse can have on weight and how fluctuations in weight can lead to serious health problems.
Substance abuse affects metabolism
Metabolism refers to the way the body breaks down food and uses it for nutrients and energy. Cells throughout the body must receive adequate amounts of nutrients, including sugar in the form of glucose to use for energy, growth, and repair from damage. Poor diet and nutrition, which often occurs secondarily to substance abuse, can lead to brain damage, organ damage, and different types of diseases [2, 3].
The body cannot store alcohol, so once it is consumed it is quickly broken down to facilitate excretion from the body. Alcohol does not contain any nutrients, but it does contain ‘empty’ calories that often make people feel as if they are full, especially if they consume large quantities of it. Large amounts of alcohol damage the intestinal tract, which then decreases the body’s ability to absorb and utilize vitamins, minerals and other nutrients from the food that is eaten .
Amino acids, in particular, are an essential source of nutrients that are contained in protein-rich foods. Amino acids are distributed throughout the body in order to boost energy production, cell growth and repair. High levels of alcohol in the body cause both the intestines and the liver to assign precious cellular resources to the removal of alcohol. This prevents nutrients, such as amino acids, from being properly utilized by the body. In a healthy body, an assortment of amino acids and other nutrients are needed to avoid organ damage and disease. Prolonged and excessive alcohol consumption interferes with these processes.
High levels of alcohol in the blood may also slow down processes in the body such as digestion, which would normally stimulate the release of vitamins, minerals, sugar, and amino acids from foods so that they can be used by cells for proper growth, development and repair.
Alcohol disrupts liver function
Alcohol abuse speeds up metabolism due to the fact that the liver has to work hard to break down the alcohol and remove it from the body . However, this hinders the liver from breaking down carbohydrates and releasing nutrients, such as glucose (sugar), for cells throughout the body.
The liver also stores excess glucose as fat that can be used as an energy source when it is needed. Unfortunately, when the liver has large amounts of alcohol to process due to alcohol abuse, it does not release the stored glucose and instead begins to swell. When fat cells accumulate in the liver due to alcohol abuse, a phenomenon known as alcoholic steatohepatitis may also develop. This condition may be asymptomatic during the early stages of liver damage, but flu-like symptoms such as fatigue, fever, nausea, vomiting and a loss of appetite usually occur during the late stage of liver damage .
Liver damage causes specific enzymes such as bilirubin to be released into the blood and alcoholic steatohepatitis is typically diagnosed if a physician detects elevated levels of liver enzymes in the blood. Once this condition has been diagnosed, there is a high risk of dying due to liver failure .
In addition, the alcohol that is processed by the liver releases toxic substances which activate the immune system, causing it to produce proteins that seek to destroy these substances. However, the accumulation of the toxins that are released from the alcohol along with the buildup of proteins that work toward removing the toxins from the body cause inflammation , especially when alcohol is consumed regularly.
Although the body attempts to quickly remove the toxins from the body, if a person chronically abuses alcohol these dangerous substances continue to accumulate and begin to affect cells in various organs. This leads to liver, kidney, heart and brain damage, among other problems such as atherosclerosis .
"The absence of symptoms often makes people think that their alcohol abuse is not causing them any physical harm, but this is usually not the actual case."In some people, it takes decades for liver damage that has been caused by alcohol abuse to present physical symptoms. The absence of symptoms often makes people think that their alcohol abuse is not causing them any physical harm, but this is usually not the actual case. Early signs of liver damage or disease include: nausea, vomiting, abdominal pain, diarrhea and fatigue. Sometimes these types of symptoms may be mistaken for other health problems such as a stomach bug or virus, but for people who abuse alcohol it may actually be the first sign of liver damage.
Signs and symptoms that occur when liver damage has reached the late stage include:
Getting treatment for alcohol abuse and dramatically decreasing the amount of alcohol that is consumed can help reverse the early stages of liver damage. Moreover, if liver damage reaches a late stage, refraining from drinking alcohol will slow the progression of the damage.
The effects of alcohol abuse on body weight
Alcohol abuse not only disrupts the body’s ability to extract nutrients from food and transport them to different parts of the body, but it also causes intestinal damage. When the intestines become irritated, digestive processes either slow down or stop and this may lead to a loss of appetite, constipation and an intestinal blockage. All of these symptoms cause people to eat less and begin to lose weight .
Eating less means that adequate amounts of nutrients will not be consumed and as a person’s weight continues to drop, poor nutrition may begin to cause a number of health problems that include :
Consuming alcohol on an empty stomach is another harmful habit that can cause blood sugar to drop to dangerously low levels. Overtime, alcohol abuse may even lead to glucose intolerance and type 2 diabetes because the liver focuses too much energy on processing and excreting the toxins that alcohol produces .
Alcohol abuse can also lead to fluctuations in weight due to its effect on the brain. If the stomach is empty, alcohol can quickly leave the stomach and reach the brain. This process is slowed when there is food in the stomach, but if a large amount of alcohol is consumed, it can still reach the bloodstream, liver, and the brain much more quickly than the nutrients contained in the food.
The liver takes about two hours to process the alcohol that is contained in one alcoholic beverage such as a glass of wine or a beer. If alcohol has been consumed excessively, it circulates throughout the body until the liver can process it. This means that, in the interim, the brain and other organs (e.g., kidney and heart) receive high levels of toxins that are released from alcohol.
Alcohol subsequently affects the brain by causing vision, speech, judgment and reasoning problems. These types of side effects may cause some individuals to eat less, forget to eat, overeat or eat foods that they would normally avoid. Forgetting to eat properly can quickly lead to weight loss, but overeating can also lead to weight gain, obesity, type 2 diabetes and other conditions such as heart disease .
Type 2 diabetes that develops due to alcohol abuse and weight loss is the result of not eating enough food, which leads to persistently low blood sugar levels and glucose intolerance. The body’s intolerance to glucose (sugar) develops because the liver avoids utilizing glucose in order to continuously process the high amount of alcohol that has been consumed.
Conversely, alcohol abuse that leads to obesity and type 2 diabetes is the result of persistently high blood sugar levels. Overeating means fats and carbohydrates are being consumed faster than the body can break them down and excrete the waste. This leads to high levels of glucose (sugar) in the blood that the liver cannot immediately process because it is already trying to remove the excess alcohol. As a result, obesity in combination with uncontrolled sugar levels can eventually also cause type 2 diabetes .
In general, alcohol abuse can lead to dangerous fluctuations in weight that may eventually cause irreversible organ damage and disorders such as diabetes. For instance, once an individual has been diagnosed with diabetes, this becomes a lifelong condition that must permanently be treated. Similarly, late stage liver disease that develops due to alcohol abuse is irreversible, although refraining from drinking alcohol can slow down the progression of the disease. Steps should be taken early to avoid the harmful effects of alcohol abuse.
The effects of alcohol on maternal nutrition and birth weight
If alcohol is consumed during pregnancy, it can cause poor nutrition for the mother as well as the unborn baby. More specifically, consuming alcohol while pregnant can lead to physical and mental problems as well as acute alcohol withdrawal symptoms in the newborn child . If alcohol or drugs are consumed during a pregnancy, the mother’s poor diet may hinder the proper growth and development of the baby and cause low birth weight .
Ways to consume alcohol safely and maintain a healthy weight
Drinking alcohol occasionally and in moderation usually does not cause health problems, but consuming large amounts on a regular basis frequently constitutes alcohol abuse and ushers in a number of different health problems. Here are some helpful strategies for consuming alcohol safely:
Eat healthy meals before drinking in moderation. In addition, eat snacks that are low in salt and fat in between drinks as this slows down the body’s absorption of alcohol.
Take days off from drinking alcohol, even if only small amounts of alcohol are consumed regularly. This deters the development of alcohol abuse and addiction patterns, as well as the onset of organ damage associated with habitual alcohol consumption.
Keep track of the types of drinks that are consumed as some drinks contain more alcohol than others. Keeping track also provides an indication of when the drinking should stop.
Drug abuse and weight
Taking recreational, illegal, and even prescription drugs inappropriately can lead to substance abuse disorders. For the purposes of this guide, a drug is defined as a chemical substance that alters the activity of the brain as well as processes in the body . Drugs often affect people differently, but the harmful side effects that most drugs cause may lead to irreversible health problems, damage and in some cases, death. This guide will focus on commonly abused drugs that negatively impact people’s lives and health.
The effects of smoking on weight
The nicotine contained in cigarette smoke is itself an addictive psychoactive substance. Furthermore, the fact that the rates of cigarette smoking tend to be higher in the demographic of alcohol and substance abusers makes its discussion here particularly germane.
Smoking is a harmful habit that reduces blood circulation to vital organs, increases the risk of developing heart disease, and speeds up the progression of heart disease in people who already have it .
Individuals who smoke heavily may also begin to lose their appetite due to heightened nicotine cravings . This, however, is not healthy weight loss as a person may simply skip one or more meals and decide to smoke instead. Although the individual is losing weight, the body is not being provided with an adequate supply of vitamins and minerals and this often results in unexpected health problems.
Some individuals actually gain weight after they begin smoking because they become more sedentary while smoking, eat higher calorie foods and exercise less .
A serious problem that often occurs when an individual stops smoking is rapid weight gain, but this appears to be mostly associated with substituting food for smoking, especially when nicotine cravings begin . The prospect of weight gain frequently discourages people from quitting, but those who do not quit risk suffering from even more serious conditions such as [13, 16]:
To be clear, the risks associated with smoking far outweigh the possible weight gain that may occur if an individual quits smoking. Furthermore, with support and discipline many people have successfully quit smoking without experiencing significant weight gain. Avoiding smoking altogether is one of the best ways to prevent unhealthy weight loss or gain.
The effects of drug abuse on weight
Recreational, illicit, and prescription medication all influence various mental processes. Certain drugs may cause temporary cognitive impairments after taking just a single dose. If this happens a person may forget to eat properly, begin to lose weight and develop dangerously low blood sugar. Individuals who begin to abuse drugs may eventually suffer from permanent impairments in brain activity as well as physical changes that lead to dramatic weight loss and poor health.
For our discussion, we’ve broadly categorized three types of drugs commonly taken by adolescents and adults. These include: depressants, stimulants and hallucinogens.
Depressants refer to substances that can slow normal processes in the body and reduce physical activity by altering the manner in which the brain sends and receives signals. Alcohol, marijuana (cannabis) and opiates such as morphine, codeine, heroin, methadone, hydrocodone (e.g. Lortab, Norco) and oxycodone (e.g. OxyContin) are all categorized here as depressants.
Codeine, morphine, methadone, Hydrocodone and OxyContin are all opiates that can be prescribed by a physician to treat intense pain or certain painful conditions (e.g., cancer). Methadone is even prescribed for some people who are addicted to heroin in order to help them overcome their opiate dependence or addiction .
Dependence occurs when the body builds up a tolerance to an opiate and an individual’s dose has to be increased in order to experience an effect. If the person abruptly stops taking the opiate, serious withdrawal symptoms may be experienced. To mitigate this uncomfortable period of withdrawal, people frequently undergo medically supervised detoxification as an initial step of substance abuse treatment.
Addiction can develop when high doses of an opiate are consumed for an extended period – causing changes in the brain that can result in compulsive cravings and can elicit drug-seeking behavior regardless of the negative effects that the addiction has on a person’s life and health.
Although opiates are commonly prescribed to treat pain, their use can quickly translate to misuse due to the sense of euphoria that people tend to experience after taking this type of drug. It is this feeling of euphoria that generally leads to opiate dependence and addiction in many people .
To varying degrees, the narcotic analgesics in the opiate class can cause side effects that include:
Side effects such as these can lead to a decrease in appetite, slowed digestion and weight loss, over time. In addition, opiate dependence and, especially, addiction can often result in dramatic weight loss when people begin to engage in drug seeking behavior more often than eating properly.
Heroin is a particularly dangerous opiate that is highly addictive. It is usually purchased on the street as opposed to abused prescription opiates. Similar to other drugs in this class, its users may display erratic drug seeking behavior, altered eating habits and weight loss if it is taken regularly .
Heroin abusers may experience a brief period of euphoria that is followed by confusion and drowsiness. Prolonged use, and the subsequent repeated cycle of euphoria/drowsiness results in the development of irregular eating habits or forgetting to eat altogether. Long-term opiate abuse also leads to extensive organ damage and disease, which is typically associated with weight loss.
Marijuana, as a recreational drug, is among the most commonly used depressants by adolescents . Excessive marijuana use alters mental processes such as memory and thinking. Most people experience short-term memory problems that may become permanent if a prolonged period of drug abuse starts. Memory problems may result in dietary changes and weight loss. However, a number of individuals who take marijuana experience a subjective increase in appetite that is frequently referred to as the munchies. This may cause overeating and weight gain.
Concentration, hand and eye coordination and reasoning problems may also develop due to marijuana use and this may make it difficult for people to maintain a healthy diet. Long-term problems that may arise from marijuana use include depression and organ damage, especially if marijuana is taken with alcohol. These types of health problems are often associated with fluctuations in weight.
Drugs with stimulant effects – caffeine, ecstasy (MDMA), cocaine and methamphetamines (e.g., speed or crystal meth) among this list – can speed up brain activity, and have the potential to increase blood pressure and heart rate. Stimulants can alter certain mental processes, with people often failing to recognize the homeostatic urges of hunger or dehydration. When stimulants are abused, this effect could result in weight loss and other, more lethal health consequences.
Ecstasy is a commonly taken illicit drug that is typically sold on the streets. A serious problem that is associated with the purchase of ecstasy involves not knowing whether the drug is made up of a pure product or a combination of other harmful substances. Commonly reported adulterant substances include amphetamine, ephedrine and over-the-counter cold remedies such as pseudoephedrine and dextromethorphan (DXM).
Taking just one dose of ecstasy can cause harmful side effects such as :
The long-term abuse of ecstasy may result in serious muscle tissue damage and the release of muscle enzymes into the blood. These large proteins can deposit in the kidneys, leading to damage or overt renal failure.
Stimulants such as ecstasy often make people feel as if they have high levels of energy and this may prevent them from realizing that they are hungry or have not been drinking enough liquids. Long-term use may result in weight loss. The relatively long acting effects of ecstasy can elevate body temperature, and an accompanying state of dehydration can become quite serious, if not fatal. As with other psychoactive drugs, changes in mental processes can a host of negative influences on a healthy body weight, especially abused for long periods of time.
Cocaine is a highly addictive stimulant that increases blood pressure, suppresses the appetite and can cause regular users to eat fewer balanced meals than those who do not use cocaine . Cocaine abuse also inhibits the ability to gauge the amount of fatty foods that are being eaten when feelings of hunger become dire .
Side effects such as these lead to irregular eating patterns and weight loss. Drug seeking behavior, which commonly occurs due to cocaine abuse, can also reduce the appetite thereby causing individuals to forget to eat properly and eventually begin to lose weight. The cessation of prolonged cocaine use leads to an increase in appetite and subsequent weight gain in some individuals.
Methamphetamines (speed, crystal meth, meth) share a number of effect on the mind and body with ecstasy, especially in regard to decreases in appetite and memory function. Of note, long term abuse of amphetamines may cause a syndrome of depression as well. Each of these side effects may result in unhealthy eating habits, weight loss and, secondarily to depression, even weight gain over time. Similar to cocaine cessation, the cessation of methamphetamines after a prolonged period of abuse has, in some cases, lead to a rebound appetite increase with resultant weight gain.
Hallucinogens dramatically alter the mind and the senses by causing people to experience a variety of sensory hallucinations – often seeing distorted images or objects that are not really there. These types of hallucinations often occur in conjunction with markedly abnormal behavior, anxiety attacks and paranoia.
PCP, LSD, ketamine and magic mushrooms all have the potential to elicit hallucinations or powerful dissociative experiences. People who take large amounts of ecstasy or marijuana may also report episodes of hallucination.
Hallucinogens can affect emotions, concentration, memory and thinking ability, as well as cause distorted vision and hearing. Drowsiness, sweating, nausea, vomiting and irregular breathing may also occur . This array of issues, particularly in those who abuse them long-term, can lead to loss of appetite and diminished nutrition and, over time, contribute to unhealthy weight loss.
The dangers of mixing drugs
People who begin to take drugs regularly or experiment with drugs may begin to mix them or combine them with alcohol. Mixing drugs with other drugs or alcohol compounds the individual risks inherent to each substance – risks like breathing problems, nausea, vomiting, vertigo, syncope (fainting), abnormal or dangerous behavior and ultimately, the risk of overdosing or dying.
Overall, drug abuse alters the mind and body in ways that make it almost impossible to maintain a healthy diet. Poor nutrition leads to serious health problems, and many diseases that may develop secondarily due to drug abuse also have associated weight changes.
Potential long-term effects of substance abuse
Dramatic weight loss due to substance abuse increases the risk of suffering from low blood sugar, heart arrhythmias, electrolyte and mineral imbalances, gallstones and alterations in blood pressure. Health problems such as these can become long-term and life-threatening.
Dangerously low blood sugar levels may lead to dizziness, confusion, tremors, trouble speaking or coma, while untreated heart arrhythmias may result in death. If the heart begins to beat too rapidly, a side effect of certain stimulants such as cocaine and methamphetamines, the heart may go into sudden cardiac arrest. Even if an individual is resuscitated, major organs may become seriously damaged due to cardiac arrest .
Losing significant amounts of weight may also result in unhealthy overeating to circumvent feelings of hunger or distress regarding the weight loss. Repeated starvation, which may result due to drug seeking behavior and other changes in mental processes that often occur concurrently with substance abuse, leads to the release of neurotransmitters that allow people to eat well beyond the satiation point by overriding their feelings of hunger.
High blood pressure, type 2 diabetes, heart disease, sleep apnea, kidney disease, respiratory problems, cancer and osteoarthritis are among the many long-term health problems that may develop due to weight gain that is concurrent with substance abuse .
In general, the abuse of recreational, illicit, and prescription drugs can all result in similarly disastrous long-term effects on health – with dramatic vacillations in body weight, both up and down.
The importance of substance abuse treatment
Although various types of effective treatments have been established for substance abuse, it remains one of the leading causes of emergency room visits and death. This, in part, appears to be because people tend to avoid seeking treatment for at least 10 years after their substance abuse has started . Due to this mismatch between available treatment, and the people who are in desperate need of it, substance abuse continues to be a major public health issue.
In addition to causing harmful fluctuations in weight, substance abuse can lead to multiple major organ damage, especially to the kidneys and heart . People who have health problems such as arthritis or diabetes tend to worsen their symptoms and even speed up the progression of their condition through drug abuse, with any associated weight changes potentially compounding the damage done.
Chronic substance abusers should be mindful of the painful, debilitating and, in some cases, life-threatening withdrawal symptoms that may develop when the drugs and/or alcohol are stopped. While not an exhaustive list, a withdrawal syndrome can encompass: heavy sweating, pain throughout the body, fever, nausea, vomiting, diarrhea and intense cravings. Even relatively mild symptoms such as these can make it quite difficult for people to overcome their substance abuse without the guidance of medical and treatment professionals. On a more serious end of the spectrum, acute alcohol and benzodiazepine withdrawal can result in dangerous seizures and even death. For these and a number of other reasons, it is one’s best interest to seek professional assistance for the treatment of alcohol and substance abuse in order to prevent or address serious health problems, and to help guarantee a positive course of recovery.
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